The Espruino's fast response time has a lot of advantages. It allows for instant execution, quick and easy debugging and is a great way to test your development projects. However, it can also be used as a traditional board through a Web-based IDE hosted on your computer. The microcontroller also uses less power than Linux Boards (although its of course a lot less powerful as well) so will run longer on battery power, it has loads of IO pins, and it can be used as an IO board for PCs, Macs, or Rasp Pis without having to program it first. The Espruino board only has one USB connector - simply take the Espruino out of its packaging, plug it in with a Micro USB cable and you're done. Check out the video below for a quick start guide!