The tools in this category are used for offline password attacks. Usually, these tools are used to do vertical privilege-escalation because you may need a privileged account to get the password files.

Why do you need other credentials when you already have a privilege credential? When doing penetration testing on a system, you may find that the privileged account may not have the configuration to run the application. If this is the case, you can't test it. However, after you log in as a regular user, you are able to run the application correctly. This is one of the reasons you need to get other credentials.

Another case is where, after you have exploited a SQL injection vulnerability, you are able to dump a database and find that the credentials are stored using hashing. To help you get information from the hash, you can use the tools in this category.