Web hosting is a service that keeps a website's files on an internet-connected computer and sends them to visitors' browsers. It is like renting a place where your shop can stay open even when your own computer is turned off.
When someone visits your web address, their browser asks the hosting computer for the page. The host sends back the files needed to show the site.
Hosting stores and serves a website, but it is not the same as designing or writing it. Someone still needs to create the site and put its files on the hosting service.