When you select the Share option and enter your collaborator's email address, you will be presented with a dropdown of sharing permissions.
Can View: Collaborator can view the document only
Can Comment: Collaborator can view the document as well as make comments
Can Edit: Collaborator can view the document as well as use the toolbar to make edits to the document
Can Share: Collaborator can view, make edits, and share with other collaborators
NOTE: You can also bulk update team member permissions, learn how here.