This is the difference between archive and delete in WhatsApp

An archived chat is not on the ‘Chats’ tab, but in a special archive. You can still view them there. As soon as someone posts a new message in the chat, the conversation is unarchived again. It is then again in the overview with all chats. You can also retrieve a conversation from the archive yourself, without writing a message. Archived chats are not backed up by the way.

Archive or unarchive a chat? Read the tip ‘Archive conversations in WhatsApp’.

WhatsApp users can no longer read or retrieve a deleted chat. Deletion is therefore permanent. You can start a new chat with someone, even if a previous conversation with that person has been deleted. The messages from the deleted chat will then no longer be visible. All chats are removable by the way. But if you want to delete a group conversation, you must first leave the group. Messages from participants in the group chat will no longer reach the person who left the group (and will reach the other participants).

Delete a chat? Read the tip ‘Remove contact and chat from WhatsApp’.