A help desk or helpdesk is a service that provides support and information for users and customers. Help desks primarily exist for computer systems or software users. However, the term may apply to many other types of products or services. A help desk may also exist within a company for its employees.
Help desks aim to troubleshoot problems or help guide users on the use of a product. For example, users of software, food, computers, apparel, or electronic equipment may call a help desk.
Who works at the help desk?
Help desks may consist of just one individual that people contact. That person has training in how to handle the problems that usually come in.
In larger companies, help desks may have several people. In fact, some of them may be experts in their field.
A telecommunications company, for example, may have a group of experts. They use software to help track the status of special software and other problems to help analyze defects.
** Telecommunications refers to communicating at a distance using hi-tech equipment.

Help desk vs. call center
The term ‘call center‘ has a similar meaning. If I want to place an order, get help with products, or track shipments I may contact a call center.
Call centers usually have more general duties than help desks. Call centers typically only deal with people outside the company or organization.
Help desks, on the other hand, may also work internally, i.e., with employees of the same company. They help other employees solve problems so that they can do their jobs.
In hi-tech companies, help desks tend to deal with more difficult problems. In other words, if the call center cannot solve a problem, it may transfer the person to the help desk.