What is website hosting?

Website hosting is essentially a means of providing people with access to your website without having to connect to your computer directly.

Once your website has been completed, you need a place to store it.  You can store it or host it on your own computer, but that introduces considerations like security and traffic congestion.

It can also be technically beyond many people's skill level to set up things like firewalls and high-speed connections.

So considering the reduced risk and manageability, it is better to have your website hosted by a third party.