There are several ways to give someone access to a web hosting account. It is up to you, the person granting access, to decide which way is best.
Via Manage team
You can use the Manage Team feature, which we have a separate guide on here. This will allow you to set up a separate login for the person who will have access, and to control what permissions that user will have.
Via the Client Area
You can also grant access to cPanel by creating a sub-account on your Client area account, according to the instructions towards the end of this guide. You will then also grant access to all or part of the Client Area.
FTP access
If you need to give access to the files on your account to e.g. an external developer, you can give that person an FTP account. We’ve written how to do this here.
Databases
If the external partner need access to databases on the account, you can fix that as well. You need to install a separate instance of phpMyAdmin and set up a database user, and we describe the process in the following instructions.