A web host is an entity that aims to provide Internet users with web sites designed and managed by third parties.
Web host provides access to all Internet content deposited in their accounts by webmasters often via FTP or a file manager software. For this purpose, it maintains computers turned on and connected round the clock internet access (eg web servers) by a high-speed connection (hundreds of Mb/s), that have installed software: HTTP server (often Apache), mail server, database …
The main activity of the web host is to install its servers, to secure (a corrugated power, backed up by a generator, an air-conditioned room equipped with fire-fighting equipment), to maintain updated with the latest security updates to prevent malicious attacks, to repair in case of failure, to settle the desired by customers or wishes to offer (such as internet programming languages and additional modules for such languages) software technologies.
Web hosting is justified by various reasons including:
- the need to secure the hosted service
- the provision by the service substantial resources (bandwidth to download …)
- support for consultancy and services associated.
IP and DNS
When a visitor requests a page from the Web browser, it asks the DNS server for the IP address of the server hosting the website. As soon as he gets the response, the browser will query this server and request this page. The web server will then search the page on his or her hard drive (if it is a static page), or building it using a script (if one dynamic page), and then send it to the browser, which displays it on the screen of the visitor.
It may be important to locate where the host has its servers. Most search engines are also based on the location of servers in order to reference a website.
Categories of web hosting
Most hosting packages are grouped into broad categories:
- Shared hosting: Each server hosts multiple sites, up to several thousand, in order to share costs. The main advantage is the price, the main drawback is that the customer is not shared server administrator, it is often dependent on the goodwill of the host if he wants a particular technology. In some configurations of shared hosting, the user can be administrator of a virtual server where the site is deployed. However, he continues to share system resources with other shared customers.
- Dedicated hosting: The customer has its own server, that can generally be administered as desired, which is the main advantage of this type of offer. The server provider, however, remains the owner of the server. The disadvantages are: much higher than shared hosting prices, and the need for skills to administer the machine properly.
- Virtual dedicated hosting via a hypervisor that offers customers the flexibility of a dedicated hosting (the client administers his machine to his liking) by providing a virtual machine that uses some of the resources of a server (physical) by technical virtualization (computing).
- Managed hosting with “managed dedicated” or “turnkey” server. The client has its own server, but the host technicians are involved in its management system. This solution is perfect if you have no technical knowledge of his administration. Simply submit their site. This type of accommodation is trying to adapt to the needs.
- Colocation: The host puts in its central data processing, a space available to the client, so that he can place his own server inside (most of the time in special cabinets or racks called “berries “). The host also provides the customer with a power supply and an ethernet cable so that it can feed its server and connect to the Internet cable. This is supposed to be cheaper, since renting the server is not understood, but the security systems and badges in data processing centers can be more expensive than renting.
Most hosts are paid. Nevertheless, there are some free hosts. In this case, the free services are often call tenders for paid benefits, most feature-rich and more efficient.
Companies face many challenges in terms of hosting their infrastructure and applications. Torn between the demands of performance for their vital activity and constraints in terms of spending and investment, they are turning more often to solutions that promote sharing and industrialization. Virtualization, the “cloud computing” and SaaS applications are increasingly being considered as alternatives to the internal web hosting.
In 2009, according to a study by MARKESS International among 150 companies, application areas most affected by external hosting are web sites and portals, followed by applications of management of customer relations, human resources, and extranets. To a lesser extent, because usually managed directly by IT departments, are messaging applications, security, storage and backup. Followed in descending order of citations but very dependent on concerned sectors:
- The applications of electronic commerce (e-commerce), intranets and collaborative applications including not only messaging features but also calendaring, task management, etc., and content management applications;
- Applications of business management and sales force management, ERP (integrated ERP), finance applications, production, and application development platforms.
Health data hosting
Since 2007, and the decision to implement a personal health record, there is a new application hosting category: the application hosting containing data from personal health. This activity is dependent on approval of the hosts, issued by a commission studying nominations since 2009. This new work highlights two facts:
- because of their critical infrastructure, hosting providers are now recognized as best able to secure information
- if our society is to facilitate access to information, the governments have to adopts measures to secure personal data via IDs of buyers, and implementation of latest encryption technology and authentication.
Translated from Wikipedia