The Difference Between Lossy and Lossless Compression

Lossless compression is dictionary based, always. If you have a 1 gigabyte file and there's 100 megabytes that repeats somewhere in the file, 7-ZIP will do every,. The compression will take several minutes, but it will find any repetition that can be fit into a dictionary and compress it down. GZIP is a streaming protocol that is, has a very short window and has moderate efficiency because it is designed so that you can send something that's a somewhat structured format like HTML or later on JSON.