FLAC is a free cross-platform audio codec format created in 2001 by Josh Colson and Xiph.Org. The name of the format is an abbreviation of the English phrase Free Lossless Audio Codec. When compressing a file into the FLAC format, it is 50-60% of the original file without loss of sound quality (especially when working with voice recordings). When unpacking such a file, absolute originality is respected. Since the format is free and open, it is supported by almost any software, it is perfect for archiving files and for regular listening to digital recordings.
AC3 is a sound file format. Its name is the abbreviation for Audio Codec 3. The format was developed by Dolby Laboratories, Inc as a modern and efficient sound compression technology. AC3 files feature Dolby Digital multi-channel surround sound. In this regard, they are widely distributed as a format for DVDs, movie theaters and game consoles. However, you can evaluate all the advantages of such files only if you have the appropriate acoustics for surround sound. An audio file of the specified format can include up to six sound channels, which creates a presence effect for the listener.