Being the RS3Analysis database page divided in three, we're introducing here the leftmost one. Even if the database has different view modes, this part is always a column.
This part of the accordion is aimed at prompting you the last 30 sessions you interacted with. The last 30 recorded, to find the most recent. The last 30 analyzed... where is that thing that I just saw? The last 30 imported, to find for example an old session that a friend just shared with you.
You can, clicking on its cogged wheel, create a smart collection, that lets you retrieve all the sessions that follow a certain rule, for example all the sessions whose vehicle-racer-track-championship fields contain a given string.
Once this part of the accordion is shown, you'll see a search edit box in it. Inserting a search string in this edit box, the database will automatically prompt you all the sessions that match the entered text. This way you can quickly test some search strings before creating a collection.
You can, clicking on its cogged wheel, create a collection of your own. You can add sessions into this collection in order to retrieve them later.
This feature can for example be useful to save all session in which you notice something that you want to show later to someone else, for example all the sessions in which you overtake someone, or all the sessions in which you notice a different temperature range.
To add sessions to the collection you need to drag the session from the database and drop it over the collection on the left.