Lakka is an open-source operating system that turns a small computer, like a Raspberry Pi, into a retro gaming console. It provides a user-friendly interface and supports a wide range of gaming consoles and platforms through the use of ROMs. ROMs are digital copies of games that can be played on emulators, allowing users to enjoy classic games from various systems on their Lakka console. However, it is important to note that downloading and using ROMs may be subject to copyright laws, so it is recommended to only use ROMs for games that you own.