Here is a speakon chasis socket (left) and a speakon plug (right).
What makes it ideal for active speakers? This cable allows 4 cores, and once wired correctly there is no way you can mess anything up. You can't accidentally invert the polarity of one driver. You also can't hook up the tweeter to the bass signal. That is a nice feature.
You can see the strain relief on the right. The cables you would use with this connector are similar to mains power cable, but with 4 core rather than 3. You can get such a cable at Decibel Hifi for a reasonable cost, but there is nothing to stop you using any cable that appeals. Multicore is simply more convenient.
Above you can see the parts. Strain relief on the bottom prevents pulling the cable from putting strain on the ends of the wires. Cables can be screwed in, or soldered.
I will be adding techflex sleeving which is reasonably priced at Chrome Audio.