In lossy compression size is reduce by sacrificing some data, but in lossless compression, the data are compressed by not deleting any data, hence not affect the quality. Also as it is a reversible process so you could easily go back to the original file.
Lossless compression uses an algorithm that rewrites the file in a way that results in smaller storage or transfer size. The algorithm does this by replacing the non- important information and store them in a file, then the algorithm reconstruct the compressed data to look exactly like the original one, as the data are stored in an index file, you can easily retrieved your original file.
We’ve put together valuable insights in the form of blogs and guides. Check’m out