From the Catechism of the Catholic Church:

1730 God created man a rational being, conferring on him the dignity of a person who can initiate and control his own actions. “God willed that man should be ‘left in the hand of his own counsel,’ so that he might of his own accord seek his Creator and freely attain his full and blessed perfection by cleaving to him.”

 

From the Compendium:

363. What is freedom?

1730-1733
1743-1744

Freedom is the power given by God to act or not to act, to do this or to do that, and so to perform deliberate actions on one’s own responsibility. Freedom characterizes properly human acts. The more one does what is good, the freer one becomes. Freedom attains its proper perfection when it is directed toward God, the highest good and our beatitude. Freedom implies also the possibility of choosing between good and evil. The choice of evil is an abuse of freedom and leads to the slavery of sin.

Find the complete Catechism of the Catholic Church and the Compendium on the Vatican website at http://www.vatican.va/archive/ccc/index.htm