I am new to couchbase lite, i am developing a mobile application using couchbase mobile as database can please any one help me how to backup data and restore it. Please explain it clearly in steps.
It depends. A typical mobile app will be synchronizing the embedded database with a Couchbase Server cluster. Your backup for the mobile app, then, is to simply replicate the database back to the app. This leaves you with deciding how you want to back up your Couchbase Server cluster.
If you really want to back up the on-device (embedded) database, you would need to copy the underlying files. This gets into implementation details, which is often a bad idea. However, the steps will be similar to using a pre-built database. You can find training on doing that here.