Gcse computer science 9 1 44 44 wide area networks

GCSE Computer Science (9-1)
Wide Area Networks (WANs)
What is a WAN?
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Web Hosting
A host is a computer on a network which offers to serve users from another location, using
the internet. Web hosting, in particular, is a service provided by various companies. These
companies ‘host’ websites on their servers so that people around the world can access
them 24/7. They will often charge a small fee for the rental of hard drive space, site
security and back up services. It is of course possible for anyone (with a little knowhow) to
host their own websites on their home PC, but for the price and risk, it is often more cost
effective and less risky to pay for a specialist company to do this for you.
Web Hosting and DNS
In order to connect to various webhosts, so that we can access the websites we need,
we use a system called DNS. In order to understand how DNS works we first need to
understand a few other important acronyms.
IP Address
This means INTERNET PROTOCAL ADDRESS. It is a unique number given to every computer
on the internet – no two computers can have the same address (e.g. 324.45.321.23). It ’ s
just like a postal address – used to identify a house – no two houses have the same
address! A device’s IP address will not necess arily remain the same each time it joins a
network or goes on-line.
ISP
This means INTERNET SERVICE PROVIDER. This is simply the company who provide you with
your internet connection.
URL
This means UNIFORM RESOURCE LOCATOR. This is simply a fancy name for a web address,
such as “ ” or “ ”.
What is the Internet?
Is the Internet and the World Wide Web the same?

Computer Science UK Membership Site Licence: Do not share outside your centre.
GCSE Computer Science (9-1)
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DNS
This means DOMAIN NAME SYSTEM. This is the system used to find the computer which
hosts the website you are looking for.
How does DNS work?
The Cloud
‘The Cloud’ is a network of servers hosted on the internet which offer a range of services
to store and process data. In particular, ‘Cloud Computing’ relates to online services
provided by numerous companies.