Bitcoin's value is flying high currently making for lots of interest in how you earn Bitcoin. One earns any cryptocurrency by "mining", which is putting your computer's CPU power to work helping to maintain the blockchain used by the particular currency. In the Bitcoin market, the only mining equipment that is profitable are expensive ASIC-based equipment running extremely custom hardware produced for the specific task of Bitcoin mining. CPU mining, or using a regular computer, is completely untenable for mining Bitcoin, but some other cryptocurrencies are still open to CPU mining.
Because the ARM-based Linux single board computers (like the Raspberry Pi) have extremely low power consumption, they're attractive for this task. The video below goes over the steps required to set up cryptomining on Linux single-board-computers for a specific cryptocurrency.
The primary advantage is their extremely low power consumption. The main cost any cryptocurrency miner faces is the electricity required to power the machine.