Web Hosting or 'Hosting' is when a company offers a physical location for the storage of web pages and files. A Web Hosting Company is like a landlord, they rent physical space on their servers allowing web pages to be viewed on the Internet.
More important than the computer space on servers that are provided for Web site files is the fast connection to the internet. An individual business hosting its own site would require a similar connection and it would prove to be very expensive. Using a hosting service lets many companies share the cost of a fast internet connection for serving files.