Freemarker is a template engine used to generate dynamic web pages, emails, configuration files, etc. It utilizes specific tags to control the output and logic of templates.

Here are some commonly used Freemarker tags and their usage methods:

1. Output value: Use the ${} tag to display the value of a variable or expression. For example, ${user.name} will display the value of the name property of the user object.
2. Conditional statement: Use <#if>, <#elseif>, and <#else> tags for conditional statements. For example:
3. If the user is 18 years old or older, they are considered to be an adult. If the user is between 13 and 17 years old, they are considered to be a teenager. If the user is younger than 13 years old, they are considered to be a child.
4. Loop iteration: Use the <#list> tag for looping iteration. For example:
5. Iterating through the users and displaying their names.
6. Define variables: Use the <#assign> tag to define variables. For example:
7. The variable “username” is assigned the value of the “name” attribute of the user. Print out ${username}.
8. Include sub-templates: use the <#include> tag to bring in other templates. For example:
9. – Include “header.ftl”
   –

   Main content

   – Include “footer.ftl”

These are just a few of the Freemarker tags, for detailed usage please refer to the official Freemarker documentation or other related resources.