Lesser Deities

The Lesser Deities, or the Teacher Gods, are the most directly involved with mortal life. Their domains focus on more abstract things, concepts such as honor or justice, things that came from mortal minds. They are called the Teacher Gods for they are more involved with teaching mortals how they should live. Lesser Deities are heavily dependent on their mortal following for power, as their domains only provide them strength when mortals actively engage in their teachings. Lesser Deities tend to have the most Clerics and Paladins, and frequently grants powers to those who follow their teachings. They also most frequently encourage their followers to spread their faiths, and come into conflict with those gods whose teachings directly contradict their own. Most Lesser Deities have their Divine Realms located in the Alignment Planes, though some swear service under the more powerful Full Deities and make their homes in the Elemental Planes.
The Lesser Deities are more vulnerable than other gods, and typically band together into pantheons with other Lesser Deities who share a common goal. These pantheons are led by the most powerful of the Deities within them, and competition within Pantheon's is not uncommon, especially with evil aligned gods.
Most Lesser Deities emerged as the sentient realization of a concept that gathered enough power from belief to gain form as a god, but some Lesser Deities were originally mortal. Mortals can ascend to godhood through several ways. A sufficiently powerful ritual can imbue enough power in a person to grant them godhood. If enough people worship someone as a god, then they can become one. This method is reportedly able to grant godhood even to those who have already died. An already existing Deity might also choose to grant a portion of their power to someone, transforming them into a god. Whatever the method, a fresh god likely has no domain, and will need to either claim one, or potentially steal power from another god, if they want to truly cement themselves as a divine power.