Merge Fields allows you to add fields from the database which pulls values from the recipient, profile, account, and sender. This allows the email be able to display important content or be more personalized. Example: If you want the email to address each recipient by their first name, you can add the $FirstName$ merge field.
All merge fields have dollar signs ($) surrounding them. For example: $FirstName$. Upon sending the email, this will get populated with the value from the recipient's profile.
You can access merge fields from the Create Email screen.
When creating an email, click the Fields tab.
You will see a few drop down boxes. Using the drop down box, select what field you would like to add into the email.
Click your cursor on the email where you would like the merge field to be inserted and then click the Insert button on the right to insert the merge field. When the recipient receives the email, the merge field will automatically display the value from the inserted field.