To be deported means to be removed from Canada by immigration authorities. People who are deported are sent back to their country of origin.
According to Canadian law, anyone who is not a Canadian citizen can potentially be deported, even Permanent Residents.
Facing deportation can be scary because people who are about to be deported face an uncertain future in their home countries. In some cases, families may be separated, and members may not ever be allowed to return to Canada.