#MOBA
MOBA stands for Multiplayer Online Battle Arena. You could say it's a combination of RPG and MMORPG, it's just that you're not going through a series of stories together. However, an arena is provided, then you play against other players online.
#RPG
RPG stands for Massively Multiplayer Online Role Playing Game. Broadly speaking, similar to RPG. Where in this game you play a character, then undergo a series of stories.