General Questions
What is a 'Network'? A network is a group of computers/devices linked together with wires (or via radio signals eg: a 'wireless' network) that have a route (or 'path') by which they can communicate with each other. The most common type of network is an 'Ethernet Network', where a cable from each device is linked into a central 'hub' which directs/controls the communication routes between devices. Each 'hub' then has a link to a further 'hub' to connect computers across a wider area (as per the Internet). Another type of 'hub' is a 'switch', which can intelligently control communication between devices. A 'router' or a 'bridge' join different 'hubs'.

What is the 'Internet'? The Internet is an international Internet-Protocol based network. In a similar concept to a telephone system, every computer/device has a unique number (an 'Internet-Protocol Address'), which can be accessed by any other number on the same network. More than one computer/device can be 'hidden' behind a single computer/device on the public network (the Internet) in a private network. This is also similar to the telephone system where a private telephone exchange can be operated on a single telephone number.
IP Networking is the basis of all computer network communications today. It was created by US Universities at the request/funding of the US Military. Their goal was to create a network which would 'self-heal' or 're-route' in the event of a failure at any point. This is the nature of the Internet today -- where communications find their way across the most preferable route at each point they meet to reach their final destination.

What is a 'Protocol'/'Service' or 'Port'? A Protocol is a standard means for information to shared between two devices on a Network. Each protocol has a particular 'port' on which it receives information over an IP Network. A Service is simply a Protocol that is in operation.

What is the 'World-Wide-Web'? The World-Wide-Web (often abbreviated to 'www') is the name given to a mechanism (the 'HTTP Protocol') for computers to share information, over a network - typically the Internet. It is sometimes used as a name for the information available across the entire Internet.
The World-Wide-Web is the basis of the Internet today. It was created by educational researchers (particularly by Tim Berners-Lee, a British Scientist based in France) to provide a way for simple information to be shared easily over the Internet (an Educational/Defence project, at that time). The HTTP protocol, was never intended to handle such vast two-way communication of rich data that we see today. However, with the popularity of accessing an enormous wealth of information with relative ease, it has survived the challenge.

What is a 'Server' or 'Client'? A server is simply a computer whose primary function is serving requesting ('client') computers with information. The term 'client' is also used to describe software that connects to a 'server' for information (eg: a Web-Browser is a 'client' that talks to a Web-Server).


Protocol Questions
What is 'HTTP'? HTTP is the Hyper-Text-Transfer-Protocol used for the collection of 'web-pages' from a server. The HTTP service runs on port 80. This is also known as the 'web' protocol/service.

What is 'HTTPS'? HTTPS is the Hyper-Text-Transfer-Protocol used for the collection of 'web-pages' from a server via TLS/SSL Encryption. The HTTPS service runs on port 443.

What is 'POP'? POP is the Post-Office-Protocol used for the simple collection & very basic management of email on a server. The POP service runs on port 110. It can operate under SSL encryption, typically on port 995.

What is 'IMAP'? IMAP is the Internet-Message-Access-Protocol used for the collection & management of email (folders) on a server. The IMAP service runs on port 143. It can operate under SSL encryption, typically on port 993.

What is 'SMTP'? SMTP is the Simple-Mail-Transfer-Protocol used for sending email messages between computers/servers. The SMTP service runs on port 25. It can operate under SSL encryption, typically on port 25.

What is 'FTP'? FTP is the File-Transfer-Protocol used for the collection & management of files on a server. The FTP service runs on ports 20+21 (also using others dynamically).

What is 'DNS'? DNS is the Domain-Name-System used for finding a particular 'IP Address'. Essentially, it makes it possible to use easy-to-remember names instead of harder-to-remember numbers to find a particular computer on the internet. The DNS service runs on port 53.


Name Questions
What is a 'Internet Web Address'? An Internet Web Address is an address made up of a Host-Name & a Domain-Name. An Internet Web Address is also known 'Fully-Qualified-Domain-Name' (or 'FQDN'). An Internet Web Address could also include a 'file path' following the host/domain name to point to a specific file, directly.

What is a 'Host(-Name)' or 'Domain(-Name)'? A Host is the first-most part of an internet name/address. A Domain is the latter part of an internet address (eg: for the web address 'www.sworddrawn.com' the Hostname is 'www' and the DomainName is 'sworddrawn.com'). The borders of classification between the two are blurred, particularly when dealing with internet addresses that are made up of more parts. Typically a Domain Name is a is a name that applies to a group of Host Names. On the public internet, different specific classes of Domain Names are set by the governing bodies and are available for purchase under set schemas (eg: [name].com or [name].co.uk).

Why do we put 'www' at the beginning of web-addresses? It is just a common policy to advertise the 'www.' host for a given domain name. It does not define what is a website or not - it is quite possible to use an alternative prefix to a domain name or none at all (eg: news.bbc.co.uk or bbc.co.uk). However, most dns-servers and web-servers are mis-configured to either provide no website or the wrong website if the 'www.' hostname is not used. Therefore it is typically assumed that a domain name needs a 'www.' appended to it unless it has another hostname appended already (eg: 'news.').