I purchased this to operate a thermostat remotely for our vacation property. We don't always know when we will be there, and it is also nice to be able to adjust the temperature after I've driven off and forgotten to do it.The Ecobee is a fully Programmable Thermostat that lets you operate it remotely over the internet. The unit does require a WIFI connection so that it can connect to the Internet. Remote access is actually done via Ecobee's servers and website. After the unit is configured for your WIFI Router it then starts communicating with Ecobee directly. You will set up an account with an Email Address and Password via the Thermostat. Once done you can now log on to Ecobee.com and access your unit. You can also do this with an Application on your smartphone (IPhone?) but with more limited capabilities. Very cool!I installed the unit myself but I'm not sure I would advise this as a DIY project unless you have some knowledge of HVAC wiring and controls. The vast majority of us do not. I have a Heat Pump and failed to initially configure the Ecobee for this, so I was struggling to understand why I had no cooling. I was having discomforting thoughts of having to call a Technician to bail me out before I baked to death in my Condo. Alas I figured it out.Traditional thermostats control your Furnace and Air Conditioning over only a few wires. In older homes that have thermostat wire with 5 or fewer strands this can present real limitations, especially for newer Two Stage Furnaces or Dual Compressor Cooling Units. Add to that Heat Pumps, Auxilary Electric heating, Dehumidification, or Humidification features, and there is no way to do this with only a few wires. Enter the concept of an Equipment Interface Module. Basically this is a separate control unit that is mounted directly to your Furnace/Air Handler and can be wired directly with a much larger selection of options. The thermostat no longer controls your Furnace directly but communicates digitally to the Equipment Interface Module using only the few wires you have in your wall. Many modern high end HVAC units now work this way. The Ecobee functions just this way.Installation.Ideally you would just mount the Module to the side of your Furnace or Air Handler. In my case it was a very tight fit to be able to service it so I purchased some 6 inch 'L' brackets from the hardware store and mounted it that way. Next I had to wire it. I searched locally for some thermostat wire to connect the module to my Furnace but no one had anything with more than 5 strands. I ended up driving further than I would have liked and found some 7 strand. I then disconnected the existing thermostat wire from my furnace and tried to connect it to the Module. This would be my communication wire. Too short! I had to splice in an piece to make it reach. Next I installed the new piece of 7 strand wire between the Module and my furnace. Finally I installed a piece of 2 strand wire from the 24VAC supply inside the furnace to power the Ecobee Module, otherwise you will need to buy an AC Adapter. From there it was just turning the breaker switch back on and getting things configured.Programming is best done from a web browser and internet connection. Use the mouse to drag the 7 day calendar, then select the mode Icon (Sleep, Awake, Away, etc.). Then select the Edit Icon to adjust the mode temperatures. Once you have figured out how this works it is a breeze. I was surprised also with how easily it connected to the internet and became accessible to me. It seems very well sorted out from that standpoint. I don't feel at all like a new adopter guinea pig. By comparison it took me hours recently just to get my E3000 Cisco WIFI router working, a technology that should now be very mature. The Ecobee is without a doubt one of the coolest gadgets I have purchased in a long time. The fact that I can actually see what the temperature is in my Condo and adjust it with a finger drag on my Iphone is really futuristic stuff.