What exactly is Ableton Live?

There are a lot of videos out there on Ableton live. However, no video explains what Ableton Live is, and can do as well as this one. This comes directly from Ableton Live's Dennis DeSantis.

As you can see from this video, DeSantis goes through a plethora of information on what exactly the possibilities are when working in Ableton. I was really pleased to see that he is working with a Novation Remote, as well as a APC40. He uses the Novation to "trigger" the keys to input the MIDI data, and moves over to the APC40 to tweak the data (knobs), to change the value of the multiple variables within the MIDI data.

The video also features DJ Jazzy Jeff and other producers and their take on Ableton Live.