PC-Network was a LAN system consisting of network cards, cables, and a small device driver known as NetBIOS.

The original PC-Network hardware was available in two varieties, baseband and broadband.

The baseband version connected computers in daisy-chain style using twisted-pair cables with RJ45 connectors. Interface cards had two RJ45 sockets for connecting to left and right neighbor nodes. The unused sockets at the ends of the network segment had to be fitted with terminators.

The more expensive and less widely used broadband version communicated over 75 RG-11-type cable on separate transmit and receive frequency ranges, using a head-end device to translate between the two signals.

When the proprietary PC Network hardware was replaced by Token Ring in IBM's later offerings, backwards compatibility with the NetBIOS Application Programmer's Interface was retained through an optional loadable program module

The original specification for category 5 cable was defined in ANSI/TIA/EIA-568-A, with clarification in TSB-95. These documents specified performance characteristics and test requirements for frequencies of up to 100 MHz.

Category 5 cable includes four twisted pairs in a single cable jacket. This use of balanced lines helps preserve a high signal-to-noise ratio despite interference from both external sources and other pairs.

It is most commonly used for 100 Mbps networks, such as 100BASE-TX Ethernet, although IEEE 802.3ab defines standards for 1000BASE-T - Gigabit Ethernet over category 5 cable. Cat 5 cable typically has three twists per inch of each twisted pair of 24 gauge copper wires within the cable.

Cat 5e cable is an enhanced version of Cat 5 that adds specifications for far end crosstalk. It was formally defined in 2001 in the TIA/EIA-568-B standard, which no longer recognizes the original Cat 5 specification.

Although 1000BASE-T was designed for use with Cat 5 cable, the tighter specifications associated with Cat 5e cable and connectors make it an excellent choice.

Despite the stricter performance specifications, Cat 5e cable does not enable longer cable distances for Ethernet networks: horizontal cables are still limited to a maximum of 90m in length.