Laplace's Hypothesis

He claims that if all the data from the universe was collected into a certain, very high-technological intellect, it would be able to determine all events in the universe. In support of this, computers presently can predict what we thought were complex things, such as weather, natural hazards and planet arrangements. This proves that we do live in a determined, consistent and predictable universe.

This is known as a mechanistic view of reality and describes the universe as acting similar of that of a giant machine. Machines work in a consistent, determinable way which to determinists, is what the universe is. The laws of nature are a good example of the universe behaving in a predictable way, for example Newton's laws of motion.

To put it into context..
Imagine a snooker shot. If we knew all the starting positions of the snooker balls, the direction the ball will move, the speed it will move etc etc, we will be able to predict the outcome of the event.
So..
Starting conditions + relevant physical laws = successful prediction of outcome

Introduction to Free Will and Determinism

What is free will?
Free will is the ability to make choices that aren't constrained by certain factors. The will is the part of a person's 'mind' which makes decisions based on multiple choices of actions. Choice here, is based on reasoning and evaluation.

And determinism?
Determinism is the belief that a determinate/precisely defined set of conditions can only produce one possible outcome given the fixed laws of nature.

Determinist Claims
Universal Causation - Every event has a cause
Causal Necessity - The same cause will operate in the same way if repeated
Reductive Physicalism - Our nature is strictly physical and can be described and understood by science