Everything has a cause (or causes) that makes it happen.

The world is completely deterministic with no elements chance.

= completely predictable in principle. Contrast with loose determinism

Determinism is true enough for practical purposes

While the world might contain elements of chance or probability — especially at the level of subatomic particles — the world or brain is "deterministic enough" to rule out libertarian free will.

An older name for compatibilism

Even if determinist is true, this has no implications for free will. "Soft ≠ soft on determinism, but rather we endorse a view of FW and responsibility that is softened up enough to fit with determinism.

Another name for "hard incompatiblism"; There is no free will

Determinism is true, and since determinism is not compatible with FW, we have no free will. (Do not confuse with "strict determinism," which makes no claims about free will). "Hard" refers to the attitude towards free will.

Free will is compatible with determinism 

. . .even with the strictest kind of determinism. This used to be called "soft determinism," but that name was misleading

Free will is not compatible with determinism

This includes both libertarians (who deny determinism) and hard incompatibilists (who deny free will).

Determinism is false, at least at the level of human action

Really another name for libertarianism

We have free will in some indeterministic sense

"Radical free will." A form of incompatibilism.

There is no free will

Determinism is true, and since determinism is not compatible with FW, we have no free will. Often called "hard determinism" 

 Based on reason or analysis of concepts

...rather than experience or experiment. The term "a priori" means "prior to experience." Claims about mathematics, ethics, and philosophy are (or should be) a priori in nature. Contrast with empirical claims.

Testable; based on experience or experiment; "scientific"

Empirical claims can only be known through experience. Questions like "How much water is in the ocean?" and "Who will win the Super Bowl in 2057?" are empirical questions. Contrast with a priori claims. (I do not like the term "a posteriori" but some of your profs will use this, because "empirical' is not confusing enough).

Our ability to act (be "agents")

 "One problem with the drug PCP is that it damages human agency."

Agency is often connected to the active/passive distinction. We are not just things to which events happen; we also make things happen, innate action, actively do things. The world doesn't just "happen to us." Ultimately, we are looking for a theory of human agency that makes sense of why we — but not grandfather clocks — are responsible for what we do. 

However, what and how to make sense of this is entirely up for grabs.