UST
Terra is a digital currency. The supply of Terra is adjusted in response to changes in demand to keep its price stable. This is achieved using Luna, the mining token whose stable rewards are designed to absorb volatility from changing economic cycles.
How does Luna and UST work?
TerraUSD (UST) was linked to a token, Luna, whose price was set by the market. Because 1 UST was defined as being equal to $1 worth of Luna, that meant that while the amount of Luna handed over in a swap for UST would vary, a holder of $1 in UST would always get $1 in value back
New Terra (no UST)
On May 25th, 2022, Terra Classic users passed governance proposal 1623, which outlined the genesis of a new Terra chain. This proposal also described a genesis distribution of Luna which would be airdropped to users of the Terra Classic chain based on pre-depeg and post-depeg snapshots. Users can find their airdropped Luna by viewing the same wallet address that was present during either snapshot and switching their Terra Station network to the phoenix-1 mainnet.
On May 27th, 2022 the phoenix-1 Terra mainnet launched, ushering in a new era of development by the Terra community.