Block Halving ETA:
New litecoins are issued by the Litecoin network every ~2.5 minutes. For the first four years of Litecoin's existence, the amount of new litecoin issued every 2.5 minutes was 50. Every four years, this number is cut in half. The day the amount halves is called a "halving".
In 2015, the amount of new litecoin issued every 2.5 minutes dropped from 50 litecoin to 25. In 2019, it dropped from 25 to 12.5. Now, in the 2023 halving, it will drop from 12.5 to 6.25.
The halving decreases the amount of new litecoin generated per block. This means the supply of new litecoin is lower.
In normal markets, lower supply with steady demand usually leads to higher prices. Since the halving reduces the supply of new litecoin, and demand usually remains steady, the halving has usually preceded some of Litecoin's largest runs.
The halving is necessary. This is how Litecoin controls its supply. Once the block subsidy expires, transaction fees will pay miners for securing the network.
Currently, there are 12.5 new litecoin issued per block.