1. Decide Questions of fact:
Good definition on WIkiPedia:
http://en.wikipedia.org/wiki/Question_of_fact2. Following instructions given by the judge on questions of evidence, procedures and points of law:
The jury may seek clarification about evidence that is presented to them in court as they might not clearly understand this evidence.
The judge explains certain court procedures to the jury as they are not necessarily aware of how the court operates. For instance, a judge tells the jury that they should not do independent research into a case, eg researching the Internet to find information that is relevant to the case that they are hearing as the accused/defendant should be judge only on the evidence that is presented in court.
The Judge explains to the jury the law that is relevant and should be applied to a case.
3. Directs the jury as the law that applies to the facts.
As above. The Judge tells the jury what law is to be applied to the facts of the case, eg. Someone who intentionally killed someone else is to have committed the crime of murder (the law makes it illegal to murder someone, therefore establishing a principle of law). The Judge tells the jury this.
4. Give rulings on points of law.
The Judge decides what law (legal principle) is to be applied to the facts of the case. This decision is based upon what the law as it is written in the statue says.