Most devices in the studio connect together with balanced XLR cables. But occasionally you come across something that has a large balanced TRS jack socket. My audio interface is such a device, with four of these line inputs in addition to four XLR mic inputs.
It's easier to use the XLR inputs, but if you run out, then this cable comes into its own. For example I've used it to connect keyboards with XLR output to the TRS line ins, and also a bass guitar via DI box. All proper balanced cable runs, that won't be subject to interference like unbalanced normal jack leads.