Jenkins Toolset allows you to manage Jenkins jobs on multiple instances of Jenkins master.
Jenkins Toolset utilizes the RESTful API that Jenkins provides. In other words, the only communication that happens is HTTP(S) communication between Jenkins Toolset and Jenkins master.
If you hit an URL like https://yourserver/job/sample-job/config.xml, you will get XML configuration file that represents the job. Imagine a situation where you need to make the same change to 500 jobs. You are lucky if you manage your jobs with Job DSL and in a more modern Jenkins infrastructure management, it should be that way but that is not the case at many software shops. Jenkins Toolset allows you to open config.xml locally in any text editor you like (who doesn't use Notepad++?), and push the changes back to your Jenkins master.
If you want to compare 2 different jobs, choose Compare from the context menu.
Use your favorite diff tool. It's configurable from settings. You can sync the jobs as you want within your diff tool. Then save the change and upload the change right from the UI.