The sections and items that show up in CCleaner for Mac's Applications tab depend on which applications you have installed on your Mac.
If an application or type of application has many features (for example, with Firefox you can delete cookies, clear the download history, and so on), that application will have its own section, and you can select specific areas you want to clean.
If an application is simply listed in the Applications sections with no details, the cleaning process will typically clear out document history, visited URLs, and temporary files for that application.
Web Browsers (for example, Mozilla Firefox and Opera)
Other applications and utilities