What is this format? (.cda)?

I got a few CDs and I wanted to copy those songs so I can play them on my slow, crappy, old PC. But all I see on the CD is files with the extension: (.cda) that were 44bytes. I copy them (assuming that the audio file is in that 44 bytes) and ejected the CD and the music doesn't work. What is (.cda) format and why can't I just copy the songs as easy as 1, 2, 3?

look herehttp://www.fileinfo.com/extension/cda

cd audio.

its a shortcut that a mediaplayer opens to use audio files

You'll need to rip the cd, coping those will not work. Windows Media Player can do it, I don't know any others.

winamp can

can vlc do it?

most likely.

Gom Player might be able to do it, but i have been wrong before.