About Litecoin:

Litecoin was created in 2011 (as the third cryptocurrency, the second was Namecoin) as Bitcoin’s fork by Charlie Lee. LTC is based on the BTC protocol, but with another algorithm. The Litecoin Network (Lightning Network) has a block time amounting to 2.5 minutes, so 4 times fewer than Bitcoin Network. So transfers are faster, but it is less secure. On 19th December 2017, Litecoin had its own ATH (All-Time High price), which was equal to 375 USD.

Resources:

Official website: https://litecoin.org/
Whitepaper: https://www.youtube.com/watch?v=Le5ByHtssnc
Source Code: https://github.com/litecoin-project/litecoin