You can easily understand what you need to do and what you are doing.
Uncheck directories will remain same as before and checked directories will be empty after cleaning.
Just click on Start Scan Button it will scan which files you need to clean and what is total size of all files.
You have options to check and uncheck directories before cleaning.
You can see what are happening inside the app at the log section.
Scan --> Choose Directory --> Clean --> Done.
Every mac user needs a good cache cleaner. So get it like others.
