There are 3 types of devices. From what I understand, the Photon lets you connect with WiFi. The electron lets you connect with 2G/3G. Source : https://www.particle.io/prototype
But what about the core device? What does it allow you to do?
@juan, you can find other vendors who’s devices take part in the Particle Cloud ecosystem. These include the bluetooth Bluz, the wifi/BLE RedBear Duo and the wifi Digistump Oak. These are supported (or will soon be) in the Particle web IDE. Most of these devices are very new, having just delivered on their Kickstarter campaigns. The Particle Photon is quite mature while the Electron still being very new, leverages the Photon’s mature code base. It’s also important to note that the Particle devices are, in my opinion, the most production-ready and production oriented devices available.