Email Commands in Freshdesk offer a way to perform activities on a ticket from your inbox, by adding a one-line command while responding to it. The activity can be anything like changing the status of a ticket, assigning it to an agent or adding a note to it.
When replying to notification emails from your agent mailbox, you can include such commands to instruct Freshdesk to perform certain actions on a ticket. The Email Command text will be stripped by Freshdesk and will not be seen by the requester, while the rest of the text will become a part of the conversation.