While heaven is community hell is isolation. It is the result of selfish choices. One writer speculates that being in hell will be like being in a windowless cellblock totally isolated. One does not know if they are there alone or if there are thousands of others. While some theologians would try to tell us there is no hell the teachings of Jesus are quite clear about its existence.
Purgatory is a place of joy.
All those in purgatory will enter heaven. They are destined for heaven however are imperfectly cleansed. Nothing unclean can enter the presence of a holy God. Purgatory is a time of cleansing. It is a state to be cleansed of our undue attachments so that we might enter the presence of an all holy God.