Below are examples of  images before and after resizing and cropping
The image below was submitted in it's original size. Not only is it so wide that you can not see the entire photo clearly in your browser without having to scroll side to side but it is 1.12 megabytes (1120 kb) in size.

The following is the same photo which has been resized at 35% of it's original width/pixel size with a compression of 25% and is now only 89.6kb in size.

The following is the same photo which has been resized at 35% of it's original width/pixel size with a compression of 25% and has had all the background grass cropped from the photo. This photo is now 39.5kb in size.