The Lawful and the Illegal in Islam - by Youssef Al-Karadhawi

Halal - Lawful. That which is permitted, in relation to which there is no restriction. And whose practice was permitted by the Legislator. God Haram - Illegal. That which the Legislator definitively prohibited; Whoever engages in its practice is subject to incurring God's punishment in the Hereafter in addition to a legal punishment determined in this world. Makruh - Not recommended. That which the Legislator disapproves of, but not categorically. Makruh is of a lesser degree of severity than haram, incurring a lesser punishment except when practiced in excess and in a way that leads the individual to haram. The question of what should be lawful and what is unlawful was one of the subjects concerning which, before the advent of Islam, the people of the world had gone far astray, allowing many impure and harmful things to be permitted, and forbidding many things that were good and pure.