Airtable was built from the ground up to support effortless collaboration. One of the main ways in which you can collaborate with other people in Airtable is by forming a team.
Once you've created a team, you can invite team members. Team members have access to all bases in their own team. You can create as many teams as you'd like for free, and each one has its own set of team members and bases.
To make a new team, click the "+" in the row labeled "New Team."
You can edit the team's title, manage the team's members, or delete the team by clicking on the button to the right of the team's title. This will bring you to the "Edit Team" menu.