A cryptocurrency that falls under the category of a stablecoin. This is tied to a real world asset, in this case the United States Dollar (USD). Each Tether is pegged to $1 worth of assets. Those are either USD or cash equivalents (bonds). This is the reserve backing the currency.
It is in this way that Tether is asset backed.
Tether is owned by iFinix, the same company that owns Bitfinex.
Many question the true holdings in reserve that is backing Tether. Following the implosion of UST, it is likely that regulation by different political bodies are forthcoming. Stablecoins are likely to be part of the new regulations. In this United States, this means the companies behind these tokens are likely going to have to register as banks. This means they will have to comply the same as any other regulated financial institution.
At some point it is safe to believe they will become an audited company.