The Torah is the Law, commonly known as the first five books of the Old Testament: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy. The rest of the books of the Old Testament are known as "The Prophets." The word, "torah," means "instruction" or "teaching," and the majority of it consists of instructions given to Moses by God at Mount Sinai.
The Law, the Torah given in the first five books, consists of three main categories. First, there is the moral Law dealing with such things as lying, adultery, theft, etc., (Exodus 20). Second, there is the judicial aspect of the Law (Deuteronomy 17:8-11) which deals with punishments, disputes, government rulings, etc. Finally, the third aspect of the law is the priestly or sacrificial system (Leviticus 7:37, Numbers 19:2). These instructions deal with how to sacrifice animals, what the priests are to do and where, etc.
The moral part of the law is based on the character of God and can never be done away with. It is always wrong to lie, cheat, and steal. However, since we are no longer under a theocratic system of government (government ruled by strict religious law), the judicial aspect of the law is not in effect. Likewise, because the priestly/sacrificial system of the Old Testament pointed to Christ and Christ fulfilled the sacrificial system by dying on the cross, that aspect of the law is no longer in effect either.