There is only one main reason why you want to speed up your website and that is to enhance the efficiency of your website. It is quite simple to achieve when you adjust images. the first thing you need to do is compressing every single image on your site and one of the best tools for this is using a Google products called Page Speed plugin that is an image compressor. Your second step is to take the compressed images and modify them to scale as it automatically reduces server lag that you would need when you re-size images online.
Thirdly is it essential to use browser caching that stores static resources and it will make a difference in page speed as well as reducing server lag too. Your fourth step is combining images in CSS Sprites. For those of you who do not know what a CSS Spite is, it is a large image, which makes up several small images, much like a collage of pictures. If you take for example twelve pictures and make one CSS Sprite image it speeds up your speed significantly. Now you let the browser to load twelve pictures at once instead of each one individually.