Sort of, every tether is not literally backed by paper USD, but the currency is inflated and deflated so that each tether is worth $1. This is done by pinning the amount of total tether to its market cap in USD. For example, if the market cap of tether rises from $15 to $20, then the total amount of tether will increase from 15 coins to 20 coins (making each coin worth $1). In short, the price of tether will always be $1 (as long as the devs stay on-top of things).
Good luck and stay safe!
In theory...In real world practice Tethers price has gone as low as $0.91 and as high as $1.06. These price swings occur during dips and rallys of high volume crptocurreny.