Something not many people know is that Dogecoin is a fork of Bitcoin—just many times removed. Bitcoin’s source code was copied and adapted to create Litecoin (LTC) in 2011. Litecoin itself spawned many offshoots, but notably LuckyCoin, which later forked into Dogecoin.
Dogecoin uses a consensus algorithm called Auxiliary Proof of Work, which allows those who mine other Proof of Work cryptocurrencies (primarily Litecoin) to mine DOGE at no additional cost in a process known as merged mining. Many DOGE holders actually got their hands on the coins in its early days while mining LTC. DOGE is also relatively fast for a Proof of Work blockchain: it can handle around 30 transactions per second, whereas Bitcoin, for example, handles only between 3 and 6.
During the first phase of mining DOGE, the cryptocurrency—true to its joking origins—was designed to yield a random mining reward between zero and one million DOGE. When it reached a supply of 100 billion DOGE in early 2018, the reward was changed to a fixed DOGE 10,000 per mined block. There is no supply cap, which was decided with the purpose of keeping the price of the coin low; capping the supply could have caused the price to rise once no more of them could be mined.