The social bees build hives and have one queen that produces all the other bees in the colony. She determines which will be workers, female bees with no ability to reproduce but born from fertilized eggs, or males which are born from unfertilised eggs. These females are the worker bees and it is their job to build and maintain the hive, care for the young and collect the pollen. The males only purpose is to mate with queen bees. Fertile queens are born when there is a need for new hives to be built.
Solitary bees only build individual nests for their offspring. All females are fertile and make cells within their nest for each egg. She collects pollen to provide food for the bees when they hatch. Within the nest will be eggs that hatch males as well as females. Once the female has built the nest and laid her eggs she will not have anything more to do with it. Some species will build their nests close to each as a group or communal, but each nest is completely separate.