Websites are hosted on a computer that is permanently online, and so available for access from any other computer around
the world. Such computers are known as web servers - or more commonly, simply servers. Outside of the major online
e-commerce sites, few organizations operate their own servers, leaving their website hosting to companies that have
the rental of web space as part of a business model. Such organizations (commonly referred to as Internet Service Providers - ISPs, or Application Service Providers - ASPs) operate server farms - banks of servers that can spread the workload of demand on hundreds or thousands of individual websites. ASPs will also normally offer a dedicated server facility, where only one site is hosted on a single server. Single page websites can be hosted for only a few pounds per year (possibly as part of a domain name registration deal), though naturally, dedicated servers cost far more.
When choosing a website host, server-related issues to consider are (1) speed of download, (2) downtime, (3) security,
and (4) IP integrity. Let's consider them in more detail:
* Speed. Like all computers, not only is technical capacity relevant (both hard- and software), but
the greater the demand, the slower the operating speed. Therefore, a small capacity server which hosts numerous websites
which each attract thousands of visitors at the same time will deliver web pages slower than a large capacity server that
hosts only one moderately busy website.
* Downtime. This is the term used to describe a website being offline. Whilst zero downtime is the
target, it is also somewhat utopian. All manner of problems from simply human error through fire or flood to malicious
attack might render a server inoperable.
* Security. How easy would it be for a hacker to access the server and so damage or delete your website
or download any information stored on it. For those sites that conduct transactions online, the use of a secure server
* IP Integrity. It is the case that at any given time there will be more websites than there are people
who wish to view them, therefore many websites will be sitting on their server with no one wanting to download them.
Hosting companies know this, and so only allocate an IP address only when a site is requested - a practice known as
dynamic IP addressing. A significant problem that can arise is that if the server is used to host websites that
infringe search engine (or email) protocols then innocent sites that share the nefarious site's dynamic IP address
might be punished along with the offending site.
A further consideration is that of having a website hosted on multiple servers spread around the globe. The advantage
of this is that if you trade (for example) in Europe, the USA and Asia then if your server is located in just one of
those then requests from the other two must travel a long way. Having a server in each of those regions will increase
download speeds in each location. It is also commonly assumed that there is an advantage in search engine optimization
to this practice where geographic search is favoured.
As with all business applications, quality of service is related to cost, therefore the requirements of the site should
be balanced against cost when choosing a server. For the likes of Amazon to have their website to go offline is a
business-disaster, even reduced download speeds will cost them sales (see mini case, 'the cost of downtime'), therefore
such companies own and maintain their own servers - and many of them.