Bitcoins and Litecoins are a type of currency, based around cryptography.
Bitcoin is one of the first implementations of a concept called "crypto-currency". Based on this concept, bitcoin is designed around the idea of a new form of money that uses cryptography to control its creation and transactions, rather than relying on central authorities.Wikipedia Wikipedia - Bitcoin
Have you ever tried to send money to someone, instantly? You may have had various levels of success, using some sort of service perhaps as an intermediary.
The problem with this is how little control you have over the transactions in these systems. You effectively give up control of your finances and place it in an intermediaries control.
Bitcoin and Litecoin are instantly transferrable to anyone without going through a payment processor
You also open yourself up to issues with the "central authority" of whoever controls your fiat money. Dollars, Euros, Yen, all have value because a "central authority" say they do. And quite often the value of those assests are affected by the policies of that authority
Crypto-currencies have no central authority, and their value is solely determined by what a person is willing to trade for them. Be it fiat or work or whatever