Display a collection of images in my webpage

This is a noob question but I'm a little confused. The thing is that I'm making a webpage which has a a lot of images that must be shown (it is a shop's website). My doubt is that I'm not sure about if I have to load this "collection" of pictures using php or javascript. I know php is executed on the server side and javascript on the client's but I don't fully understand the difference. Thank you all.