The feature comes handy in situations when you have handed over your smartphone to a friend or family member that you do not want to see all your chats. Archive chat feature is available for both individual and group chats.
What does archiving a chat mean?
When a user archives a chat, he/she is essentially hiding it from the main chat list. The feature does not delete your chat, nor does it back it up to your SD card.
As per the WhatsApp FAQ page, archived chats will stay archived even when you receive a new message from an individual chat or group. Also, you will not receive notifications for archived chats unless you are mentioned or replied to.
How to archive a chat on WhatsApp?
In order to archive an individual chat, follow these steps
You can follow the same steps to archive a group chat. Simply, tap and hold the group chat you want to archive and tap on the Archive icon.
How to archive all your chats on WhatsApp?
WhatsApp also allows you to archive all your chats. Follow these steps to archive all chats on Android smartphones
Apple iPhone users can archive all chats at once in WhatsApp Settings > Chats > Archive All Chats.