Web hosting is how your website remains visible to the worldwide public even when you turn your computer off. eg in the simplist terms, someone somewhere needs to leave a computer on with a reliable live connection, so that other people can see your website.
However, we use very high spec'ed servers (dedicated computers) in a quality data center, with highspeed redundant internet connections, uninteruptable power supplies, etc. Your hosting fee alsocontributestoward ourhelpdesk and advanced CMS services.