Well, my friend once explained web development to me like this:
You have three people working on a site:
- First: Designer, who designs how site's gonna look (Using, let's say PhotoShop)
- Second: Front-End Developer, who makes what designer designed and site's functionality (Using HTML, CSS, JS....)
- Third: Back-End Developer, who does his own job (Idk what back-enders do, sorry)
I hope this was helpful :)