Put simply, web hosting provides a place for your site to live on the Internet.
Every site is made up of files, code files to build the pages, image files for the visuals, etc.
These files need to be stored somewhere they can be accessed quickly anywhere in the world, 24 / 7.
Many people ask us why they can't just host on their home PC.
Firstly, the code that runs web servers (special types of computers) needs many different types of software that aren't on an average home computer.
Most importantly, though, what if your home PC was turned off? If your web site files lived there, your site would be turned off too!