Here's what Boss Electronics have to say:

The TE-2 Tera Echo represents a milestone as the 100th model in the long history of the BOSS compact series. Starting with the release of the OD-1 Overdrive in 1977, BOSS’ legendary stompboxes have been integral tools of artistic expression for millions of players around the world. Fueled by a spirit of dedication and innovation that began nearly four decades ago, the TE-2 carries on the BOSS legacy of bringing inspiring, leading-edge technologies to musicians everywhere.

 the TE-2 delivers an amazing new ambience effect that satisfies and inspires. Complex internal processing produces an incredibly deep and spacious sound, dramatically enhancing the straight guitar tone without overwhelming it. Through the TE-2’s simple, familiar stompbox controls and incredible sensitivity to your playing dynamics, an extremely wide range of sounds can be achieved. And with the expressive Freeze function, you can hold the current effect sound to create rich soundscapes for lead playing and sonic exploration.