What are template tags in WordPress?
 

Template tags are used within themes to retrieve content from your database. It is a piece of code that tells WordPress to get something from the database.

The author template tag displays the name of the post author in WordPress. Template tags can also return a data set and users can choose what to display using parameters. Template tags are basically PHP functions, so any PHP function defined by a WordPress plugin or theme can be used as a template tag.

Template tags are used to fetch and display dynamic data.
You can get more details about Template tag to use it.