Some prophets wrote things, while others had people write things about them.  Thus, there is a mixed bag about the Hebrew prophets.  Generally speaking, a prophet was someone who believed that a higher power had contacted them.  Thus, they became the intermediary between Yahweh, their God, and their fellow human beings.  Almost like angels, these humans delivered a divine message.  Quite often, the message itself that the prophet conveyed was called a prophecy.  The Hebrew prophets were moral teachers.  Some prophets may have had a role with the institutional Temple priests.  Many religious groups have had what are called prophetic priests.  The Hebrew word navi, meaning spokesperson, has been traditionally translated as prophet.  These navi was considered to be the mouth of Yahweh or God, since they were open to receive and transmit his divine wisdom.  Besides writing and speaking messages from God, these Israelite Nevi’im often acted out prophetic parables in their life.  They were not always praised, since some prophets were even considered bad or false prophets.  Thus, they were sometimes the target of persecution and opposition.