When you want a picture to be smaller you can use resize or resample.

When you get this option box, type the numbers you want into the set new size boxes.  Pixels are the tiny dots that  make up the  bitmap image screen, if you are viewing it 1:1,  you will see it as the number of pixels you type in here. So the image is limited to the size you type in there, unless you zoom in, which will result in a grainy look.  There is a limit to the size you can shrink a  picture to without loosing resolution.

Next, Saving the resampled picture.

Graphics  One

Graphics  Two

Graphics  Three

Graphics  Four

Graphics  Five