mp3

[Wispy68]

Why is there a '3' in MP3?

[brooklyn77]

My guess...and its only a guess...

Is that they already used MP1 & 2 so 3 had to come next.

If the next question is "why use numbers at all" maybe its because they knew there would eventually be more than one MP format.

All the above may be a load of rubbish, but it also just may be true

[brooklyn77]

Just had a look at something else...it seems that MP (or MPEG) is a compression format, its what is used to compress data onto your PC otherwise the file would be very very big.
the 1 2 3 and 4 is the 'Layer' number.

In effect from what I have read, MP comes from MPEG (a compression format) and the number refers to the 'Layer' or in lamens terms its number 1,2,3 and 4, --- in sequence.

Go to
http://en.wikipedia.org/wiki/MP3#Development
to read more

[Wispy68]

Thank you for a really interesting answer brooklyn.

Cheers!