Litecoin is a digital currency. If Bitcoin 1.0 is Windows 98 then Litecoin is Windows XP. Litecoin runs Bitcoin 2.0, this is; Faster, More secure, Cheaper to transact, Vastly larger capacity, Backwards compatible to Bitcoin 1.0 and Future technology ready (lightning, mast, atomic swap..). Litecoin has been running since 2011 and has a very big capacity so you won't have problems of slow and expensive transactions like you had with Bitcoin 1.0. New applications that use Litecoin's enhanced capabilities are in the process are being developed and because of the huge number of things you're going to be able to do I think it's the most exciting digital currency.