Chat is for questions. Tasks is for work. If something would take several steps and a few minutes (going through a folder of new contracts and flagging anything unusual, for example), describe it on the Tasks page and let it run. Previous tasks stay in the list on the left so you can reopen them anytime.
A task works through your knowledge library the same way chat does, so it only ever sees what you already have access to. Nothing outside your library happens without asking you first.
Open Tasks
Open Tasks from the center action row (when Tasks is enabled for your org). Previous tasks sit in the list on the left.
Describe the outcome
Type the result you want and press Start.
Watch it work
Steps check off as they finish. If the task asks permission, answer it and the work carries on.