In Facebook, DM stands for Direct Message, which is a private message sent to a specific user on the platform. It is a feature that allows users to have private conversations with each other, similar to text messaging or email. Direct messaging on Facebook requires the recipient to "like" your page beforehand. Users can send direct messages to anyone even if they are not friends, and these messages go to a message request folder which the receiver must approve to continue the conversation. Facebook Pages can only send a direct message to accounts that follow their page. The restrictions for messages vary for each platform. For instance, on Facebook, users must “like” a page before you send them a DM.