Entropy based

• Run Length Encoding : look for same symbol recurring consecutively
• Huffman (Adaptive, Static) : Sorted symbols to add up the two least frequencies to be coded 0, 1
• Shannon-Fano : Sorted symbols with total frequency approximately half to be coded 0, 1

Dictionary based

• LZ77 : Search into the input sequence within a sliding window for longest match in buffer.
• LZ78 : LZ77 + Inserts one- or multi-character, non- overlapping.
• LZW : LZ78 + Dictionary indexed by codes.