what means 4:3

Hi All.

What are the implications of a projector that is 4:3 (I guess this is 1.33) - say in reference to "cover" images for different sections? If I have some of these and they are 24" x 14" (1.7) does this basically mean that .4 of my image is going to be cut horizontally? I mean, I will lose image on the left and the right of these cover is that right?

thanks.