A help esk is an information and assistance resource that troubleshoots problems with computers or similar products. Corporations often provide help desk support to their customers via a toll-free number, website and/or e-mail. There are also in-house help desks geared toward providing the same kind of help for employees only. Some schools offer classes in which they perform similar tasks as a help desk. In the Information Technology Infrastructure Library, within companies adhering to ISO/IEC 20000 or seeking to implement IT Service Management best practice, a Help Desk may offer a wider range of user centric services and be part of a larger Service Desk.