There are many audio formats available when it comes to ripping music and burning to the CD. MP3 is lauded as the most widely used format to compress audio file without compromising on the quality of the music. On the other hand, FLAC (Free Lossless Audio Codec) is basically an alternate to MP3, but it is not as widely used by people as MP3 is.
The major difference between both the audio file formats is their compression method to compress the digital audio information. The MP3 is a lossy format that uses a compression method which discards the parts of the music which people usually are not likely to listen to. On the other hand, FLAC, as it name suggests, do not discard any part of the music file, and make it available to you with all the information contained as in the original file.
Therefore, the quality of the sound will never change, even if your compress or decompress the FLAC files multiple times. On the other hand, the sound quality starts deteriorating if you compress and decompress the MP3 files multiple times.
The difference between lossy and lossless formats brings difference in the size of both the file formats. If you compress a WAV file in MP3 as well as in FLAC format, then the size of the MP3 file will be around 20% of the size of the corresponding FLAC file.
For instance, if a WAV file has a size of 40 MB, then the size of a FLAC file will be 20 MB and 4 MB for the MP3 file with 128 kbps constant-bit-rate.
The disk space matters a lot when it comes to saving music files on portable devices. That is the reason why MP3 format is so popular among people all over the world. Also, you will find few devices available in the market, which can play FLAC files. Usually, you will find only high-end devices with capability to play FLAC files.
Another major difference between the two is that MP3 is a proprietary format while FLAC is royalty-free software. Even though, MP3 is a popular format, yet, only few people know that it is a proprietary format and one has to pay for the royalties, in order to play MP3 format.