Lossless Compression can reduce files without loss of information in the process.
In lossy Compression reduce the file size be eliminating bits of information. It permanently deletes any unnecessary data.
Lossless Compression is ideal for documents containing text and numerical data where as Lossy Compression is ideal for image, audio and graphics.
Lossless Compression method provides an average 2:1 compression ratio where as lossy compression has a higher compression ratio that is 25:1 or compression ratio.