Disk Types
I use 2 different types of CD's - CDA and CD-ROM.

CDA
CDA is the full and correct name of a regular CD (CD Audio) - this type traditionally plays in a hifi, car, computer etc. The CDA format has a maximum capacity of 75 minutes (1 hour and 15 minutes) playtime, and is higher quality than mp3, but for the spoken word is neglegible.

CD-ROM
CD-ROM's, also known as data CD's are used to store computer data.
Most audio files on this site are in mp3 format (data). There are a few WAV files which are higher quality, but larger files.

MP3 files and CD-ROM's
Mp3 files are audio (usually music/spoken word) data files and there's no specific maximum playing time when put on a CD as the files can be of varying quality, so it's the total size of all the files, to a maximum of 700 megabytes. So theorhetically a single CD-ROM could contain 10 full albums (or more) in mp3 format - as an example. There is something called 'bitrate' which equates to the quality - the higher the biterate (192kb is average), the larger the file, the more space it takes up.

MP3 files and Compatibilty
Mp3 files will play on all computers - Windows, Mac, Amiga, Acorn, laptops, tablets, smartphones, mp3 players etc, and on some modern HiFi's, TV's and DVD players.

CD or CD-ROM ? Tell Me Which.
So, when ordering, please be sure to state if you want...
  * CDA (75 mins). Playable in your car or on your Hifi etc.
  * CD-ROM (mp3). Playable on your PC etc.