There are 2 ways to start the node agent :
Browser : if Jenkins node agent is launched from a browser, a JNLP (Java Web Start) file is downloaded. This file launches a new process on the client machine to run jobs.
Command-line : to start the node agent using the command line, the client needs the executable agent.jar file. When this file is run, it simply launches a process on the client to communicate with the Jenkins master to run build jobs.
