The cable you're describing is commonly known as a "USB to RS232 adapter" or a "USB to serial adapter." These adapters allow you to connect devices with RS232 serial ports to a computer or other device with a USB port. They're often used to connect older equipment such as serial printers, scanners, or industrial machinery to modern computers that lack RS232 ports. The "2.0" in your description likely refers to the USB version, which is USB 2.0 in this case. These adapters are handy for situations where you need to interface with legacy hardware using modern computers.