Why do most audio src tags use ogg and mp3

Question

I have noticed that most tutorials regarding HTML5 audio tags always use mp3 and ogg formats, Why do most developers use mp3 and ogg format in their html5 audio source tags? Why can't it be mp3 and wav? Is it a rule of the thumb to use mp3 and ogg on audio source tags?

Answer 1

Wave is generally uncompressed audio data, which is not practical for web applications.

Answer 2

mp3 and especially ogg are easy to stream and can contain video/audio/text

as mentioned above .wav is totally uncompressed-audio only