If you are a modern radio ham, you deal much with the RS-232 Serial standard.
High-Frequency ham gear has had a computer interface since at least the 1990s. The common name for this interface is Computer-Aided Transceiver -- CAT -- a term coined by Yaesu I believe. Using the CAT interface, one can read or change the frequency of the radio, change bands, and adjust the majority of controls found on the faceplate of the radio.
CAT is a "staple", and the minimum level of automation for both local and remote control of an amateur station. Some modern radios use USB (The Universal Serial Bus) for CAT. USB is bit harder to automate in remote situations, but not impossible.
Beyond CAT control of the radio, there is control of other auxiliary components in the station -- amplifiers, rotators, antenna switches, and keying mechanisms for CW/PTT.
RS-232 and the modern Windows computer
In order to interface your radio or other peripheral to your PC, be it a laptop or desktop, you need to have an RS-232 port. Since the mid 2000s, most PCs do not have a built-in RS-232 port. Typically, an RS-232 port is installed by either installing a PC card in a slot in the computer or by using something called a USB-to-RS-232 cable.
What makes the Edgeport products better than the rest?