A Jenkins job is a specific task or set of tasks that Jenkins can run. An example of a Jenkins job could be to build a software package, run tests, and then deploy the package to a server.
A Jenkins pipeline is a set of interconnected jobs that can be used to manage the entire software development process from code check-in to deployment. An example of a Jenkins pipeline could be a build job that checks out the code from a version control system, runs tests, and then triggers a deployment job that deploys the application to a staging environment.