http://cointelegraph.com/news/114247/tether-integrates-with-cryptsy-expanding-its-digitized-dollar-service
the core of tether (USDT) is that 1tether(USDT) is equal to 1$(USD).
How does Tether work?
Tethers exist on the Bitcoin blockchain through the Omni Protocol. The Omni Protocol is open source software that interfaces with the Bitcoin blockchain to allow for the issuance and redemption of cryptocurrency tokens, in our case, “tethers”.
Tether Platform currencies are 100% backed by actual fiat currency assets in our reserve account which are instantly redeemable in a one-to-one ratio with those reserve currencies. Therefore, 1 tether USD₮ will always equal 1 USD.
The Tether Platform is fully reserved when the sum of all tethers in circulation is greater than or equal to the balance of fiat currency held in our reserve. Through our Transparency page, anyone can view both of these numbers in near real-time.
For a more detailed technical explanation of how the Tether Platform works, please download the Tether white paper.
more info here:
https://tether.to/faqs/