Word
Session
A session is one continuous stretch of work with your agent, which remembers what was said inside it and nothing from before it.
Also called: a fresh session, chat session
You open one with your agent, you work, you close it. Inside one it remembers what you said; across two it does not.
You'll meet the word constantly, because most of the habits in this course exist to survive the gap between sessions: a notes file, a rules file, a commit made while something works.
The same word also means one stretch of being logged in to an app, which is why your own app has a setting with session in its name. Different thing, same word.