Your archived emails aren’t kept in a folder like your “ trash” or “important” folders instead, they’re found in All mail. However, they’re still kept in your Gmail account.
When you archive your messages, technically you’re removing them from your inbox.
Here, you can access and retrieve them (move them back into any folder/label) at any time. In Gmail, this means moving email messages from your inbox into “All Mail,” where they are stored on the Gmail server. Essentially, it’s a way of saving and protecting the data in emails that you don’t want to keep in your inbox, while letting you retrieve them quickly.