Whatsapp creates automatic backups of your conversations, but you can also create a manual backup.
On iOS, navigate to Settings, and then Chat Settings, and then Back up Chat, then tap Back up now.
On Android, simply create a backup, simply navigate to settings and then tap chat settings and backups.
However, this may not be a backup of your media,
But you have to use a file manager to copy the media folder
/ SD card / WhatsApp / Media
Unexpectedly, there is no way to restore the live chat from WhatsApp, however, if you want to restore backup, you will need to uninstall and re-install WhatsApp Messenger again.
If you start WhatsApp again after reinstalling, you should request to restore your most recent backup.
Just follow the given guidelines and all of your chats should be back.