LZ4 is a fast compression algorithm designed to provide high-speed data compression and decompression. It is particularly useful for applications where speed is more critical than achieving the highest compression ratio. LZ4 is widely used in various software and systems, including databases and file formats, due to its efficiency. The algorithm works by identifying repeated sequences of data and replacing them with shorter representations. This allows for quick access to compressed data, making it ideal for real-time applications. LZ4 is open-source and has been adopted in many programming languages, enhancing its versatility and accessibility.