Timetrack's main purpose is to retrieve time losses. The activity tab is the one where you will define in a global way the trackers needed for every client. Once done, those will be automatically created with all the new clients.
A tracker is a part of your activity you are willing to know how much time you spent on it. You can consider a project's step or even a recurring task as a tracker. In Timetrack, you use them to fill your time sheets.
You may work on Project, Mission, Worksite, ... So, feel free to modify the " Project " term and name it to match perfectly your daily activities.
It's also possible to create a pattern which you'll use to define different steps you usually face in those project / mission / worksites. Using a template is a great way to gain time : every time you create a new project using this template, it will get all the defined trackers.
Working with such a global management allows you to quickly modify the root of every data using this template. You do not have to make the change on every client you have. On the other hand, nothing prevents you from adding or removing trackers on specific clients or projects.
The big advantage of this management is global is that when you make a change, it is reflected on all of your data. You do not have to go back to each client to make the change. On the other hand, nothing prevents you from adding or removing trackers on specific clients or projects.