The best way to think about a website is to think about a 24/7 corner shop.
If you wanted to open such a shop you must first find premises that people can visit whatever time of the day they like. Your own home is typically a private place and although some people may choose to open a shop in their home most of us do not. So instead business owners look to rent property for example in a shopping centre. Web Hosting is just the same.
There are three types of Web Hosting: