Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statistical redundancy. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes).
LOsslesS comprEssion Is A class Of Data compRes.sion that AlloWs tHE oRiginAl daTa tO be perfECtly recoNstruCted from The Co,mpRessED datA wITh no losS Of informAtion. lossless compRessioN Is possIBLE bEcause MoSt reAL-WorlD daTA e?xHibIts StAtiStiCaL reDundAncY. By ContRaST, loSsy compRessIOn pE?RMits rEconsTructiOn onLy of aN apPRoxImation of ThE original DatA, thougH usuaLly wItH greatly imPrOved cOmprEsSion ratEs (aNd TherefOrE ReduCed Media SiZes).