The Jenkins master is the term for the computer that manages all Jenkins build activity. It provides a web interface for users to interact with, and it can delegate build activities to other computers (Jenkins slaves). One Jenkins master can be used to manage many slaves.

A computer connected to the Jenkins master. This computer will run build jobs for the master. Slave computers may all be configured the same, or some may be used to provide specific tools (e.g., those that can only run on one operating system, such as Xcode), or different versions of the same tool that will not co-exist on the same computer.

A series of build steps executed one after the other in a single workspace in order to do something useful for the developer (e.g., compile an application, generate a test report, etc.).

This is the smallest unit of work in Jenkins. It comprises a single action (eg., launch Ant/Gradle/Maven with a target, run a batch script, delete a file).

A folder in which a Jenkins job runs its build steps. This folder may be on the Jenkins master or one of the Jenkins slaves, and it may be in a different place (or on a different computer) every time the job runs.

A collection of Jenkins jobs that are tied together to perform a larger workflow (e.g., compile > run tests > generate reports). Unlike build steps in a job, jobs in a pipeline can be executing simultaneously.

The end product of a build job (e.g., an .apk or .app file for building a mobile project).