During human life we can either accept or reject God's grace. When we die, we will be judged according to our works and faith. As a result of this particular judgement, a person may be united with God in heaven, may undergo a purification in purgatory before being united with God, or, because of his or her choices, may enter hell, which is total separate from God.
Defined as: a state of final cleansing after death of all of our human imperfections to prepare us to enter into the joy of God's presence in heaven.