LZ77 and LZ78 are two different types of lossless data compression algorithms. They were both published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978. Both of these types of algorithm, LZ77 and LZ78, are mainly designed to compress data without destroying the contents of the data when decompressed. Like all data compression algorithms, LZ77 and LZ78 both use a process called "data compression", or just "compression". Additionally, LZ77 and LZ78 both have their own processes for decompression (a type of process which reverses compression).