Controls how Jenkins schedules builds on this node.
Utilize this node as much as possible
This is the default and normal setting. In this mode, Jenkins uses this node freely. Whenever there is a build that can be done by using this node, Jenkins will use it.
Only build jobs with label restrictions matching this node
In this mode, Jenkins will only build a project on this node when that project is restricted to certain nodes using a label expression, and that expression matches this node's name and/or labels. This allows a slave to be reserved for certain kinds of jobs. For example, to run performance tests continuously from Jenkins, you can use this setting with # of executors as 1, so that only one performance test runs at any given time, and that one executor won't be blocked by other builds that can be done on other nodes.