There are 5 key stages to team development according to the Tuckman model. This YouTube video explains each step:

Tuckman’s Ladder: 5 Steps of High Performing Team Development

Bruce Tuckman conducted research on teams and identified 5 stages of team development that a group needs to progress through. A manager who understands these stages and the needs of people at each stage can help the team progress through to the performing stage, and become a high-performing team.

These stages are:

1. Forming,
2. Storming,
3. Norming,
4. Performing and
5. Re-forming.

Each of these is explained in more detail in the video and the accompanying article. You can read more about this model by following this link to read How to Develop an Effective Team with The Tuckman Model.