Term
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Definition
| Central Processing Unit; responsible for carrying out the instructions contained in a computer program |
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Term
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Definition
| Most information is stored in one of two places--the main computer memory or the computer hard disk. |
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Term
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Definition
RAM stores information on computer chips using a series of electronic switches.
Switches are either turned on or off
Information in main memory is lost when the computer is turned off.
Main computer memory is relatively expensive. |
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Term
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Definition
Information stored on the computer hard disk is stored magnetically.
Retained even when the power is turned off.
Cheaper per byte. |
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Term
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Definition
Devices used to get information from the user or to present infomration to the user.
Monitor, keyboard, mouse...
Exgternal devices (peripherals--printers and scanners) |
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Term
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Definition
| Application Software and System Software |
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Term
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Definition
| Programs used for productivity or entertainment purposes |
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Term
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Definition
Used to manage the computer
Operating system
Windows and MacOS
Graphical interface for the user allowing her/him to start and stop programs and manage files |
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Term
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Definition
CPU can only execute instructions that are in main memory
Instructions copied onto main computer memory from hard disk
Saving--copies current data specific to task onto hard disk |
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Term
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Definition
CPU is bottleneck which limits the overall performance of the computer
Main CPU and other processor specifically for graphics |
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Term
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Definition
| Used to overcome the processor bottleneck\Break down the problem our computer is working on into separate tasks which can be executed by multiple processors working simultaneously |
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Term
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Definition
Each switch represents a single binary digit (BIT)
Byte= Eight bits
Words= Organized set of bytes
Address= Reference number for each individual byte |
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Definition
| Reference number for each individual byte |
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Term
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Definition
Random Access Memory
Computer can change contents of RAM at any point |
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Term
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Definition
Read Only Memory
Information cannot be changed
Switches have been glued either on or off
Negligible compared to RAM
Modern ROM can be changed (Flash ROM)
Contents are still kept when the computer is turned off |
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Term
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Definition
Small amount of memory that is even faster than main memory
Stores information that is frequently accessed |
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Term
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Definition
Extends the amount of apparent main memory by using a section of the hard disk which acts as if it were additional main memory
CPU can only access information in main memory
Allows us to run more programs at once than we would normally be able to |
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Term
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Definition
| Programs run slowly and the hard disk churns due to excessive switching between programs and lack of real main memory |
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Term
| Serial and Parallel Connections |
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Definition
Serial--connection bits are sent through the connection one at a time
Parallel--multiple bits are passed through simultaneously over different wires in the connector
(Newer connections--single bits are faster speeds) |
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Term
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Definition
USB (Universal Serial Bus)
USB 2.0
IEEE-1394 (Firewire)
Bluetooth
Wi-Fi |
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Term
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Definition
anchor tag
end tag
href (hypertext reference)
Example:
URL |
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Term
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Definition
| Specify the name of the protocol, the name of the webserver and the name of the file which the web browser should retrieve |
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Term
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Definition
Used to create links between files which are located on the same webserver
It assumes that the webpage referred to is found at the same location as the current webpage |
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Term
| Creating a relative reference to a file in another folder |
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Definition
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Term
| Absolute vs. Relative References |
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Definition
| Relative references make a website more portable |
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Definition
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Definition
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Term
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Definition
| [image]
All image tags require an alt attribute |
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Term
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Definition
JPEG- Photographs
GIF- Non-photographic images
PNG- Non-photographic images (more advanced) |
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Term
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Definition
align="value"
values include:
top
bottom
middle
left
right |
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Term
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Definition
height and width attributes
pixels
percentages |
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Definition
Unordered
Definition
Numbered |
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Term
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Definition
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Term
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Definition
definition list
definition term
definition description |
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Term
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Definition
Start Table
Table Row
| Table Data
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Term
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Definition
colspan (to make a cell span more than a single column)(use with td or th)
rowspan
width/height of cell (use with th or td or tr) |
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Term
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Definition
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Term
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Definition
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used to create sections within an HTML document
attributes:
align (center, right, left) |
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Term
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Definition
24 bit color (like PNG)
lossy |
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Term
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Definition
256 color maximum
effect of watching a movie by stringing many images together into a single file
lossless |
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Term
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Definition
alternative to GIF
allows for semi-transparent images
24-bit color (16.7 million colors)
lossless |
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Term
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Definition
Every computer is connected to a central hub computer
Any computer except the central hub can fail without affecting others |
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Term
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Definition
| The form in which the computers on a network are connected together |
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Term
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Definition
The computers are linked into a ring
When a computer wants to send a message, it sends it to its neighbor on the right (counterclockwise)
If one of the computers fails, messages won't be able to make it around the ring to their destination |
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Term
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Definition
Computers are connected directly to a central called a bus
Contention issues--multiple computers may try to send messages out on the bus at the exact same time |
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Term
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Definition
Twisted pair cables (similar to phone line)
Coaxial cables (similar to cable television line)
Fiber optic cables |
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Term
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Definition
| Local area networks (small) |
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Term
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Definition
| Metropolitan Area Networks (within a city or small region) |
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Definition
| Wide Area Networks (connects states, nations or even continents) |
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Term
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Definition
| Connects together the same type of network technology |
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Term
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Definition
| Wide Area Networks (connects states, nations or even continents) |
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Term
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Definition
| Connects together the same type of network technology |
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Term
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Definition
| Special-purpose device that connects different types of technology |
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Term
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Definition
The range of frequencies in the electromagnetic spectrum that a medium can use to send information
Broadband or Narrowband |
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Term
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Definition
Connects a computer to another computer using the standard telephone service
Uses a modem (converts from bits and bytes to an analog tone that can be transmitted over a telephone line)
56 kilobits per second maximum |
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Term
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Definition
DSL
Takes the unused bandwidth from copper telephone wires and uses it to transmit digital information
Speed varies according to subscriber's distance from the telephone company's central office |
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Term
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Definition
Uses the cable used to bring television
1.5 megabits per second or faster |
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Term
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Definition
Slightly oversized telephone cable
100 megabits per second |
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Term
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Definition
| Other types of connections |
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Term
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Definition
Protocol is a specification
Defines how programs written to support the protocol should act
More than one program can support the same protocol |
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Term
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Definition
Application layer
Transport layer
Network layer
Physical/Data layer |
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Term
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Definition
Defines actual control and data transfer needed for specific applications
Wide range of different protocols for e-mail, web, IM |
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Term
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Definition
Builds on Network Layer
Supports error detection and correction
Provides transport of unlimited amounts of data |
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Term
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Definition
Responsible for transferring data across the Internet
No error checking
Data limited to small size "packets" |
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Term
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Definition
Defines physical connections between computers in network
Determines how 0s and 1s are sent on medium (eg voltage levels) |
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Term
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Definition
Every computer on the Internet has its own
Assigned when a computer is first connected to the Internet
Four numbers between 0 and 255 separated by dots
Used by network layer (help route messages on the Internet) |
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Term
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Definition
Used at physical/data layer
Allocated on the basis of which company manufactured a particular card
Do not provide any information as to where the computer is located
Routing of messages within an individual LAN |
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Term
| Packet Switching vs. Circuit Switching |
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Definition
Telephones are circuit switching based (quality of connection remains constant)
Internet is packet switching based (all circuits shared) |
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Term
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Definition
Hypertxt Markup Language
computer language used to define layout and formatting information on webpages;
not a program |
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Term
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Definition
| like grammar rules used in HTML, determine if sentance/construct is legal |
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Term
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Definition
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Term
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Definition
| We take unformatted text and mark ip up for display on a computer; HTML is a markup language-- markup is done in a standard text editor |
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Term
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Definition
| Word, unlike a standard text editor, displays text as it is seen. There is no need for markup, all formatting is done within the file |
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Term
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Definition
HTML tags tell the computer how to display a webpage.
They often work in pairs
Start tag <>
End tag </>
Start & end tags create a container for text
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Term
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Definition
| Can be added to tags to provide additional information |
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Term
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Definition
The "container" includes
start tag, end tag, and contents |
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Term
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Definition
16 standard colors for HTML; 16.7 million custom colorscreated w/ hexidecimals
Red, Green, Blue |
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Term
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Definition
.xls (excel)
.doc (word document)
.txt (text)
.html (what html must be saved as to open!)
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Term
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Definition
Part of syntax rules-- sets of formatting tags can be used together, but must be properly nested
<b>an example of <i>nesting</i><b>
(must be closed in order!!!) |
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Term
| In-Line Tags/Text Level Tags |
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Definition
tell text what to do
bold <b>
italics <i>
underline <u>
inc font by 1 <big>
dec font by 1 <small>
changes size, color of text or font face <font> |
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Term
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Definition
control larger amounts of text
paragraph <p>
line break in text <br />
headers <h1>...<h6>
horizontal line <hr />
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Term
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Definition
| formal language that defines how humans communicate with a computer |
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Term
| File level tags/HTML tags |
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Definition
These are necessary for all HTML pages!
start of XHTML <?xml>
<html> all contents of html
<head> used by browser, not displayed
<title> listed IN head, displayed in web title bar (can't contain formatting)
<body> actual content-- including background/text color
must close each of these! |
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Term
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Definition
| Computer programing language associated with HTML |
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Term
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Definition
| Getting rid of bugs/errors so source code can validate and work properly |
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Term
| HTML Table & Separating into Multiple Columns |
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Definition
| Columns created with <table> and single <tr> row and one <td> table data for each column |
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Term
| Navigation & Advertising Sidebars |
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Definition
Created with table columns! ie <td> within a <tr>
Navigation usually on left.
Advertising on right. |
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Term
| Vertical Placement of buttons & ads |
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Definition
| Each button/ad has its own <tr> with a single <td> |
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Term
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Definition
| empty <td> w/ specified heighth |
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Term
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Definition
| empty <td> with specified width |
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Term
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Definition
| Used for complex projects; built in steps/stages & checked before going on |
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Term
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Definition
The <body> tag has a background attribute that allows to set image as background of body;
if not big enough, repeats! |
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Term
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Definition
Transmission Control Protocol
Provides application built on top of it with a direct connection between any two computers on the Internet
Implementation of the TCP protocol takes data sent by an application and breaks it into chunks small enough to fit into individual IP packets
The TCP implementation sends the packets through the Internet
TCP numbers the packets and reorders them if necessary when they are received
Automatically resends a copy of a packet if it is lost
Associated with specific applications |
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Term
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Definition
Does not identify which application running on the original computer sent the message or which application on the recipient computer should receive the packet
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Term
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Definition
Simple Mail Transfer Protocol
Used to send mail from one computer to another
E-mail is usually sent to a mail server computer |
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Term
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Definition
An alternate naming scheme supported by application level programs
ex: www.whitehouse.gov
A computer can have multiple hostnames (usually only one)
Converted into IP number by computer
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Term
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Definition
Model of computing
Two different types of computers participate: client computers and server computers
Client comps: multi-purpose
Server comps: dedicated single-purpose; sends webpages to client comps upon request |
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Term
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Definition
Two or more computers cooperate to carry out a task
Neither computer is in charge
Ex: Chat application
Requires fewer resources
Reduces legal liability for file sharing programs |
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Term
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Definition
Text in one part of a document may be connected to text in other parts of the document via links
Replacement for books
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Term
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Definition
header can be made in body before <table>
w/ <h1 align="center"><font size="" face="">...</h1>
or an image can be added, but use the <div> tag to center!!
<div align="center">
<img scr="blah.gif" alt="blah"></div> |
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Term
| Ads as images in ad column |
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Definition
can hae multiple rows w/ images in <td>
remember to set border="0" on ad's <img> tag
provide height and width for better display |
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Term
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Definition
-single row tables w/ multiple columns a <td> for main and a <td> for sidebar!
-remember valighn="top"
-fix width attribute within <td> tab
-placement within a sidebar can be controlled w/ inner <table> contained in sidebar <td> |
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Term
| Navigation sidebar (multi-page) |
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Definition
-home should be saved as index.html, can be copied
-must organize files first on comp (location scheme)
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Term
| Example navigation tab html code |
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Definition
<tr><td><a href=index.html">
<img src="buttons/home-button.gif" alt="home" border="0" width="x" height="x" /></a></td></tr> |
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Term
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Definition
Uniform resource locators
used to identify specific files, web pages, and other information at a much more detailed level than that provided by hostnames and IP numbers
Begins with an identifier determining what kind of information is being referenced
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Term
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Definition
<font> tags are limited to in-line text;block elements illegal
so:
<p><font face"sans-serif" size="4"></font></p> |
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Term
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Definition
<body background="images/background.gif">...</body>
browser repeats pattern, vertically...so play w/ gif |
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Term
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Definition
| Hypertext Transfer Protocol |
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Term
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Definition
GET-most common request, requests that a webserver send a file
HEAD-requests information on a file
POST-requests the information that a user has entered into the webpage form, webserver sends back the results |
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Term
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Definition
example: HTTP/1.1 200 OK
ERRORS are displayed here |
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Term
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Definition
| Consists of a header type followed by a colon ':' followed by a corresponding value |
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