what is it
The stakeholder map is a representation of all the stakeholder involved in a project, aimed at clarifying roles and relationships. Depending on the specific need, the map can be created as a simple quadrant with two axis (level of influence and level of interest or engagement in the process), or as a more complex motivation matrix (detailing what each stakeholder brings to each of the other ones through the service project).
use it to
Reflect on the different positions and define how to deal with each of them.
Consider the broader ecosystem that sorrounds the project: you may discover additional partners to involve or blockers to avoid.