The Internet is a massive global network of sub-networks...
And explaining the exact technicalities of how it works would take a whole series of in-depth posts; as there are so many dependent technologies.
But for a simple outline of how it all connects together, take a look at this diagram:
You can see from this diagram that:
- A network is a cluster of computers that can talk to each other.
- The internet is a vast global network of inter-connected networks.
- A web-server is a computer that ‘hosts’ websites and makes them available to the internet.
- There can be 00’s or 000’s of Websites on a single web server – or conversely, a big website can need multiple servers.
- ISP’s connect to the global web network via very fast dedicated data connections.
- ISP’s send data up and down your phone/cable line to your modem/router.
- Your router acts as a hub for several PC’s to access your home network and share the internet connection.
- Wireless 'WiFi' enables connections for Handheld devices/Smartphones (like iPhones & iPads etc.)
- A PC uses a computer application called a browser to communicate with the internet. A Browser understands the languages that a web-page uses to 'draw' itself and provide interactivity. There are many languages, but the most basic are HTML & CSS.
- You interact with the web-page and the browser sends hyperlink clicks, data and requests for more information down the line to the web-server - which then communicates back with more data, which can be text, pictures, audio & video etc.
- Search Engines are commonly used to find what we want on the internet. Google is the best known example.
The Wikipedia definition: “The World Wide Web, abbreviated as WWW or W3 and commonly known as the Web, is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them via hyperlinks.”
Broadband Connection & ISPs (Internet Service Providers)
Although faster broadband has speeded up file transfer massively over the last few years, it's still important for web designers to minimise file sizes to allow for older browsers or slower connections. It’s also good practice to reduce the amount of bandwidth required for any website - as the opposite is just wasteful!
Broadband 'bandwidth' is typically quoted in Megabits (as opposed to Megabytes.) Most standard (not fibre/cable) broadband connections these days are around 8-20 Mbit; although your actual connection speed will vary - depending upon 'contention', the quality of the line and the distance from the junction box out in the street. 'Contention' is an ISP term defining how many people are also sharing a certain allocated bandwidth.
An 8 Mbit connection means that theoretically 8 million bits (1 million bytes; 1000 Kb; 1 Mb) can be transferred per second, although some of the connection bandwidth is used for error-checking, so even a 'perfect' line would never quite achieve these speeds. Most homes in the UK for instance will actually get somewhere between 2-16 Mbit via a standard telephone line, which would give maximum download speeds of around 200-1600Kb per second. Some rural areas still have pretty poor standard broadband speeds (1-5Mbit), but many people find that moving the fibre gives a huge increase, as the technology works differently.
Fibre networks (via standard phone lines) are extending this in many areas to 40-80 Mbit - providing downloads speeds of 4Mb-8Mb per second. This is what is known as 'Fibre to the cabinet' (FTTC), and essentially means that the broadband connection is fully digital to your local street cabinet, and the last leg is via your phone line.
Direct cabled networks can provide fibre to the premises (FTTP) and impressive speeds of 50-1000Mbit (1Gbps)!