public Bruce W. Tuckman (1965) defined four stages of group development that groups go through. These are:
Forming
First orientation phase. People have different experiences. And they know about it. So they are polite and cautious.
Storming
Team members start focusing on project. Conflicts - in values, priorities, processes, etc. - become visible (see Zwischenmenschliche Konflikte). In development teams, this might concern test coverage, review process, coding guidelines, definition of done, definition of ready and more.
Norming
Team spirit develops. First successes support the team solidarity. Team commits more and more to its own processes. Team members become more self confident and open.
Performing
This is the stage where performance starts to peak. This includes motivation, creativity and flexibility. The team members know their responsibilities.
Further reading
https://www.ibim.de/techniken/4-1.htm https://agilecoffee.com/toolkit/tuckman-model/