Variable tags are unique tags are replaced when you send customized/personalized content such as emails, microsites, and PDFs.
Contact Tags - Contact Tags are used to personalize content toward the recipient. They can also be used as sort fields. When an email is sent, the Contact Tags are replaced with the contact's information. Example: "Dear [first_name]," will be changed to "Dear Jane,".
Profile Tags - When an email is sent, the Profile Tags are replaced with the logged in user's profile account information. Example: "Sincerely, [p: first_name]" will be changed to "Sincerely, Laura".
https://yourplatform.dmplocal.com/main/index.php?p=variable_tags.list