Products vs Services
In the Catalog, you can create Products, i.e tangible goods, or intangible goods, i.e Services rendered by a person.
Set the Type field of a Product to differentiate between a physical Product and a Service. By default new Products are created as physical Products.
When a Product of Type 'Service' is added to a Quote or Invoice, you can specify the Staff, i.e. person in your team or user in your account, who will be performing the work.