What Is a Web Host?
Bear in mind that a web site is a collection of files.
Those files must be stored on a computer somewhere.
And they have to be readily accessible to anyone, anywhere in the world, who has an internet connection.
Including when there are a large number of people all wanting to access the website at the same time.
That's where a web host comes in.
A web host is an organization whose business is providing large, powerful computers (servers) where the files for a large number of websites are stored (hosted).
The files for each individual website are stored independently of the files for other websites, either on their own dedicated server or on the same shared server, but kept separate and independent by the hosting software.
You will start off with a shared server, but move to dedicated as your business grows and succeeds.