In Jenkins, all the settings, build logs and configurations are stored in the JENKINS_HOME
directory. Whenever you want to create a backup of your Jenkins you can back up JENKINS_HOME directory frequently.
It consists of all the job configurations and slave node configurations. Hence, regularly copying this directory allows us to keep a backup of Jenkins.
You can maintain a separate backfile and copy it whenever you need the same. If you want to copy the Jenkins job, then you can do so by simply replicating the job directory.