Shared web hosting is that type of hosting in which your website is hosted on a server with hundred of other websites means you are sharing your website with many other websites. On a shared web server each website has its own domian name. Each web site has its own space in the server and no other website can use another's space.In shared web hosting you have no acess on the server but you have full acess on your website through control panel. Shared hosting provides multiple software solution like email, database and other editing options.Shared web hosting is the most commonly used because it is cheapest from other web hosting like dedicated hosting and virtual private hosting. In sahred web hosting provider includes system administration to prevent the use of server resouces.
Shared hosting services mainly uses web based control panel system, such as cPanel, Direct Admin, Plesk, InterWorx, Helm, H-sphere, Enism, Sphera or one of many other control panel products. In this type of hosting Web Hosts ( companies who provides server) maintains all the softwares. It is the responsibility of web hosts to upgrade the hardware and software and also to maintain the up-time. The web hosts provide all type of Technical Support and other services. Most of servers based upon Linusx operating system due to low cost. But there are many web hosts who provide Microsoft Windows based or FreeBSD based solution.
Implementation of Shared Web Hosting :
Shared web hosting can be implemented by two ways: Name based Or IP Based, some control panels a mix of Name based and IP based on one sever.
IP- Based: In an IP Based hosting each website or domain has its own particilar IP address. IP based is also called dedicated IP hosting. For example if server hosts ten websites then it should have ten unique IP address. The Web Host can configure these IP address either by adding physical network interfaces to the machine or by adding alaised network interfaces to the computer. In the IP based hosting, web server software determine the IP address of the website which user want to see and then connect with that website. The main reason for using the IP based hosting is that thorgh this each website will able to use his private SSL certificate apart from the shared certificate.
The main disadvantage of IP based hosting is that if web host hosting a large number od website on its server than it is difficult to allocate different IP address for each website and also difficult to maintain it.
Name Based: In Name Based hosting there are multiple hostnames with a single IP address. It is also called shared IP hosting. Like IP based hosting there is no requirement of giving the different IP address to each web site. Every website share one common IP address. In Name based hosting the web host configure the DNS server to match each hostname to the same IP address and also configure the HTTP server to recognize the different host names. Whenever an internet user rquests for the web site from a web server using HTTP/1.1. An HTTP/1.1 request contains the Host and Header which told the host or webiste the user want to see. The web server uses this information and then searches the hosted website to show it to the net user.
The Name based hosting has some disadvantages also:
It will not work if the browser does not send host name along with its request just as in case of HTTP/1.0 browser.
Name based hosting does not properly support to secured websites (HTTPS). All the name based hosts must share the same SSL certificate.
If the DNS is not working properly then it is difficult for the name based hosting to distinguish between various hostname. In this condition default host is sent back to the internet user.