Customer support is a range of customer services to assist customers in making cost effective and correct use of a product. It includes assistance in planning, installation, training, trouble shooting, maintenance, upgrading, and disposal of a product. wikipedia.org

Hardware troubleshooting is troubleshooting applied to computer hardware. Troubleshooting is a form of problem solving, often applied to repair failed products or processes. wikipedia.org

A computer repair technician is a person who repairs and maintains computers and servers. The technician's responsibilities may extend to include building or configuring new hardware, installing and updating software packages, and creating and maintaining computer networks. wikipedia.org

A network administrator, network analyst or network engineer is a person responsible for the maintenance of computer hardware and software that comprises a computer network. This normally includes deploying, configuring, maintaining and monitoring active network equipment. wikipedia.org

Technical support or tech support refers to a range of services by which enterprises provide assistance to users of technology products such as mobile phones, televisions, computers, software products or other electronic or mechanical goods.

A help desk 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 e-mail.

Customer service is the provision of service to customers before, during and after a purchase. wikipedia.org