User permissions allows you to invite your team to Portal, but limit what they can see or do on your account.
For example, you can invite a technician to look up products, view proposals and download the Installer PDF, but hide all your costs and profit. Or you could have Sales staff that you want to let create orders, but maybe you don't want to let them submit the order. You can do all this and more with Permissions.
Check out a quick overview: