Different audio formats: MP3, ACC, AIFF, WAC and FLAC
Lossy: Lossy compression is compression where when the file is compressed, some of very minor details are thrown away in order to made the size smaller but this does not affect what you hear and what you see.
Lossless: Lossless compression is when a file is compressed and the size is smaller, but no quality is lost
Bit rate: Is the rate of which bits can be transmitted per second across a network
Take away: You can see that The video above was converted from MP4 – MKV and during this the file size enlarged but because it was a compressed file, when it was enlarged it did not have the detail that was already lost therefore you can see the MP4 file looks better then MKV.