Clients in Runn provide a way of grouping projects together under a single entity.
For most use cases, this will be an external business that you are undertaking the project for. However, some customers use clients for internal departments, or for different groups within their business, we have even had someone use airplane hangers as clients and planes are projects.
The choice is yours and it can be anything that suits your requirement. It is simply used as an easy way to group, filter and see totals of projects.