Imported Accounts are accounts you import using a private key string or a private key JSON file, and were not created with the same Secret Recovery Phrase as your wallet.
For this reason, these accounts will not appear automatically when you restore your MetaMask account with your Secret Recovery Phrase. The data associated with your MetaMask Secret Recovery Phrase cannot be added or extended to the imported account, and importing an account previously does not associate it in any way with the Secret Recovery Phrase associated with your wallet.
Therefore, it is important that you keep the information you use to access imported accounts separately and safe to ensure the recovery of these accounts in the future (similar to how you should keep your Secret Recovery Phrase backed up offline).
Imported Accounts are shown on the MetaMask interface. You may see this tag by:
Clicking on the icon at the upper right corner next to the network indicator tag to open the dropdown menu.
For information on how to import accounts, see here.
