LZ77 and LZ78 (algorithms)

LZ77 and LZ78 are the names for the two lossless data compression algorithms published in papers by Abraham Lempel and Jacob Ziv in 1977 and 1978. They are also known as LZ1 and LZ2 respectively[1]. These two algorithms form the basis for most of the LZ variations including LZW, LZSS and others. They are both dictionary coders, unlike minimum redundancy coders. LZ77 is the "sliding window" compression algorithm, which was later shown to be equivalent to the explicit dictionary technique first given in LZ78.
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