Web hosting is a rented place on a server where a website's files are kept, so that anyone on the internet can open the site at any time. There are two main kinds. With shared hosting, many small websites sit on one server and split its cost. With managed hosting, the host also looks after the updates, the backups and the security.
Take, for example, a dental clinic in Nagpur that wants a six-page website: the doctors, the treatments, the fees, the timings, a map and a form to book an appointment. The clinic's web designer builds it with WordPress, a free program for making websites that many small businesses use. The site needs to be kept somewhere. The designer buys a shared hosting plan for about ₹2,500 a year.
The plan comes with a control panel, a website where the designer manages the hosting without typing commands. In the panel, she installs WordPress in one click, uploads the photos and creates two email addresses for the clinic. She points the clinic's .in name at the hosting server, through the domain's DNS records. She also switches on a free certificate, which shows the padlock in the browser. A certificate authority issues it. The site is live the same afternoon.
Why is shared hosting so cheap? One server may hold several hundred small websites. Each site needs very little computing, because a clinic's site gets perhaps 50 visitors a day. So the cost of one server is divided among hundreds of customers. Sharing one machine among many customers, each kept apart from the others, is called multi-tenancy. The weakness is that the sites share the server's processor and memory. If one site on the server suddenly becomes very busy, the others can slow down.
Managed hosting costs more, often several times as much. The host updates WordPress and its add-ons, takes a backup every day, scans for harmful code and restores the site if it breaks. A clinic has no IT staff of its own. For such a customer, managed hosting does the work that would otherwise be forgotten.
When does a site outgrow web hosting? Say the clinic grows into a chain of 15 clinics, and patients start booking through an app. The app needs its own backend and a database. The chain then moves to a virtual private server on a developer cloud, where it controls the whole server. An online shop has a third choice: an e-commerce platform, which includes the hosting.
To load faster for visitors in other cities, a hosted site can also sit behind a content delivery network, which keeps copies of its pages and images near the visitors.