Litecoin was created in 2011. Charlie Lee, the founder, is a former Google employee. After getting familiar with bitcoin, he decided to create a new cryptocurrency that would complement bitcoin and offset some of its disadvantages.
To achieve the goal, Charlie Lee introduced a fork based on bitcoin source code. Litecoin differs from Bitcoin primarily by a decreased block generation time (2.5 minutes instead of 10 minutes), an increased maximum number of coins and different hashing algorithm (Scrypt rather than SHA-256).
While bitcoin is regarded as "gold" and store of value for long-term purposes, litecoin is considered "silver" and a cheaper everyday-purpose means to carry out transactions.
Litecoin supply is strictly limited to 84 million LTC. In contrast, bitcoin is capped at 21 million BTC.