How many agents do I need?

[pigit]

I want to deploy on three different servers. Can I do this with one agent or how many do I need?

[Tim Crall]

The reason to have multiple agents is if you need them due to mutually incompatible requirements (i.e. windows agents and linux agents) or because you need them to reduce wait times.  Otherwise you should be able to use a single agent.

[Jobin Kuruvilla [Adaptavist]]

You can do it with one agent, as long as the agent can connect to the 3 servers. It depends on where you are deploying and how you are deploying.

In short, agents doesn't represent where the code is deployed it. They are the servers where the actual build is done. If your process needs the deployment to be done in the target env, then you will need as many agents.