"Tether is a stablecoin with a 1-to-1 peg against the USD, whereas the conversion rate is 1 Tether USDT equals $1 USD. For every Tether USDT in circulation, $1 USD is added to a centrally managed savings account as a collateral. However, some people doubt that Tether is actually fully collateralized."
Stable coin” is a term used in cryptocurrency to describe cryptocurrencies meant to hold stable values. For example, Tether (USDT) is a blockchain based asset meant to trade for $1 USD. It is a “price-stable cryptocurrency.”
There are a number of stable coins in circulation today, and a number more have been attempted in the past (with varying degrees of success).
Each stable coin has a unique mechanism, but they all generally work the same way. They hold collateral of some type and manage the supply to help incentivize the market to trade the coin for no more or less than $1. For some, like Tether or TrueUSD, the concept is to hold actual dollars in reserve that are redeemable for the token. For others, like Dai, they hold crypto assets in reserve and have a lending system.
copy paste from here
https://medium.com/@argongroup/stablecoins-explained-206466da5e61
Hence the quotation marks.