Prayer is a form of communication, a way of talking to God or to the saints. Not all prayers are the same, however. Here are brief descriptions of the five major types of prayer.
In prayers of adoration or worship, we praise the greatness of God, and we acknowledge our dependence on him in all things. The Mass and the other liturgies of the Church are full of prayers of this sort, such as the Gloria (or Glory to God). Among private prayers, the Act of Faith is a prayer of adoration.
Prayers of love or charity are just that—expressions of our love for God, the source and object of all love. The Act of Charity is perhaps the best example of a prayer of love.
Prayers of petition are the type of prayer with which we are most familiar. In them, we ask God for things we need—primarily spiritual needs, but physical ones as well. Our prayers of petition should always include a statement of our willingness to accept God's Will, whether He directly answers our prayer or not. The Our Father is a good example of a prayer of petition, and the line "Thy will be done" shows that, in the end, we acknowledge that God's plans for us are more important than what we desire.
Perhaps the most neglected type of prayer is prayer of thanksgiving. While Grace Before Meals is a good example of a prayer of thanksgiving, we should get into the habit of thanking God throughout the day for the good things that happen to us and to others.