The cable is a perfectly normal mini jack cable, with mini jack 3.5mm At both ends, it is the same cable that the vast majority audio system uses to transmit sound, it is also the same connector as almost all smartphones, tablets and smartphones have, except for the iPhone 7 , however, it comes with an adapter for it.

The cable here can thus transfer stereo audio from your music player to your system. 

The cable is analog but that's how the plug plug is in all devices so you don't get out that your devices don't support each other if they have such a connector like this.

The mini jack plug is in all installations and all speakers whether they are wireless, use 30pin, lightning or something completely different, it's such a connector that's in any device.

Your TV definitely also has the plug, sometimes it even has 2 of them, one if you want to put an extra speaker to your TV and another if you want to use your TV as a speaker for another device.