Crypto Almanac - Part 280 Beginners Guide

Source. Crypto info.com

What is Tether?
Tether (USDT) is a blockchain based stable coin, which means it has been designed so that every USDT coin in existence is backed up by one US dollar. This allows it to be used as a medium of exchange and a storage of value, instead of experiencing the wild price swings of other cryptocurrencies like Bitcoin.

In theory the price of USDT should stay very close to one dollar at all times, allowing traders to avoid dealing with fiat money every time they want to buy and sell cryptocurrencies. This has made USDT a popular option according to CryptoCompare, who have cited data showing that 80% of all Bitcoin trading is done in Tether.

Tether Limited is the company that holds the US dollars in reserve to back up USDT.