This CD ROM contains two versions of each picture.
A big PRINT (high res) and a small print (low res) version.
Every computer picture is made up of 1000’s of tiny dots called pixels, just like a puzzle.
high resolution
low resolution
A high resolution picture contains huge numbers of dots (in this case 300 per square inch)
A low resolution picture contains less dots (in this case only 72 per square inch)
big PRINT (high resolution) pictures can be printed at large sizes without becoming blurry.
Small print (low resolution) pictures are better used for small documents.
You might also want to think of your computer’s memory.
If your computer is very old, then opening big PRINT (high resolution) pictures and working with them, can take a long time. So perhaps you should stick to small print (low resolution) pictures.