Called Sub Accounts or Accounts, this functionality allows you to separate clients on different sub accounts. You can think of them as folders.
It is especially important if you work with multiple clients because all the team members that you’ll invite (most likely the client at least) they’ll have access to all the projects in that sub account. The invitations happen at the sub account level, not at the project level.
This functionality helps with being organized as well and separate personal projects from client work.
This is a PRO Studio feature if you want unlimited sub accounts. You’ll get the main account in Free and Personal plan as well but you’ll need to upgrade if you want to create more.