A web hosting service is a type of Internet hosting service that hosts websites for clients, i.e. it offers the facilities required for them to create and maintain a site and makes it accessible on the World Wide Web. Companies providing web hosting services are sometimes called web hosts.
Typically, web hosting requires the following:
one or more servers to act as the host(s) for the sites; servers may be physical or virtual
colocation for the server(s), providing physical space, electricity, and Internet connectivity;
Domain Name System configuration to define name(s) for the sites and point them to the hosting server(s);
a web server running on the host;
for each site hosted on the server:
space on the server(s) to hold the files making up the site
site-specific configuration
often, a database;
software and credentials allowing the client to access these, enabling them to create, configure, and modify the site;
email connectivity allowing the host and site to send email to the client.
