Generally speaking, there are two kinds of Airtable collaborators: workspace collaborators and base collaborators.
A workspace collaborator has access to every base in a workspace. Consider inviting someone as a workspace collaborator when you know that you'll be working on many different bases together with this person and you want that person to be able to see all of the information in the entire workspace.
A base collaborator has access to a single base at a specified permission level, but is unable to see the workspace in which the base is located, or any of the other bases contained in that workspace. Consider inviting someone as a base collaborator when you want to directly work together with someone on a base, but don't want to give them access to all of the bases in a workspace.
How to add a workspace collaborator
A workspace collaborator has access to all of the bases in a given workspace. To add a workspace collaborator, tap the Workspace Collaborators dialog in the Edit Workspace menu:
This will bring up the Manage Collaborators menu. From here, you can tap the Add workspace collaborators option, and enter the email address of the person with whom you wish to collaborate.
Once you've selected a collaborator, you will be prompted to select that collaborator's permission level. To finish adding the collaborator, tap "Add."
How to add a base collaborator
A base collaborator has access to an individual base, without having access to all bases in a workspace. To add a base collaborator, go to the base to which you would like to add a collaborator, and tap the Collaborators button in the top right-hand corner. This will bring up that base's Manage Collaborators screen.
From the Manage Collaborators screen, you can tap the Add base collaborators option, and enter the email address of the person with whom you wish to collaborate.
Once you've selected a collaborator, you will be prompted to select that collaborator's permission level. To finish adding the collaborator, tap Add.
Generate invite links
In IOS, you can also generate an invite link which will grant access to anyone with the link. Choose "Create a link" in the Manage Collaborators screen.
Next, set the permission level and optionally restrict who can use the invite link by choosing a domain for the email of all new collaborators. In this example, the domain is set to @airtable.com but you can set to any email domain.