An IT infrastructure technician in the UK is responsible for maintaining and supporting computer hardware, software, and networks in an organization. They play a crucial role in ensuring the smooth functioning of IT systems and helping to maintain productivity. They are also known as first or second line support and are responsible for actively maintaining the organization's IT assets.

A network infrastructure technician is responsible for modifying and configuring network settings and components, as well as installing network cabling and fiber. They also handle basic firewall and router implementation, monitor network performance, and conduct simple analysis and documentation of configuration management.