User names are used to identify an individual that uses a shared system or resource. User names are needed for several reasons:
- Security: Shared resources can be granted to individuals based on their user name, preventing people that shouldn't have access to a particular resource.
- Privacy: If you protect your account with a combination of a user name and a passWord, it can help to prevent other people from seeing things about you. If you host files with your internet service provider, they would be protected by a user name and passWord so only you can see them.
- Accountability: Contributions made to something like Answers.com are associated with a user name so that everyone knows who to thank for good answers.
The benefits of a user name vary widely and depend on to what you are identifying yourself.
