Working with freelancers and external contractors

Inside Bitrix24, we work with internal employees, but what if you need to work with external performers or a customer? Shouldn't we invite them as employees to the portal? 
As a solution, there is the Bitrix24 Extranet, which allows you to work with external users, but at the same time prevents them from accessing internal information. 
To invite an external user, you must create a workgroup or project. It is within this group or project that all work with external users will take place.