Session

A session is an individual "episode" of a role-playing game; generally a pre-arranged time when the players and GM can get together to continue the narrative of the RPG and advance the storyline. Note that in most games a single story arc may take several sessions to actually play out; or, one session may include bits and pieces of several storylines.

The most popular frequencies for sessions are once a week, once every two weeks, and "whenever we can all get together (don't hold your breath)". Which one is used depends on the players' schedules.