The internet - Coggle Diagram
The ‘cloud’ or ‘cloud computing’ refers to a range of software and services that are run on the internet.
- Streaming services e.g. Netflix, Spotify
- Online applications e.g. Google docs, Office 365
- Online storage e.g. Dropbox, Amazon web service
- Online backups e.g. Mozy
- Online hosting of web pages e.g. 1 & 1, Fast hosts
You can access data from any device with an internet connection
It is easy to share files with other users
Multiple people can work on the same file simultaneously
Your work is automatically backed up
If you don’t have an internet connection, you can’t log in and access your files
If you forget your login details you can’t access any of your files and media
There is a risk of hackers being able to access your private data and files
Some cloud services charge an ongoing monthly or annual fee
Web sites need to be saved or hosted on a web server. This is so that other computers can access them over the internet.
There are two different methods of hosting:
Benefits of local hosting:
Speed - hosting your website locally on your computer means that it will run much faster than if it were hosted on a server in a different country
It is less expensive than external hosting as there is no rental charge
It gives you full control of your web site.
Privacy – you may want a website for your own use.
Disadvantages of local hosting:
You need technical knowledge to host a website locally
Your computer always needs to be switched on – otherwise the site will be unavailable
Bandwidth can be an issue – especially if your web site is popular
You are responsible for the backups
Most people choose to host their website externally.
External hosting is where you pay a web hosting company a monthly fee to host your web site on one of their servers.
You don’t have to worry about running out of bandwidth - however you may be charged for additional bandwidth.
The hosting company will maintain the server and ensure that it is always available.
The hosting company will perform regular backups, virus and malware scans
External hosting can be expensive
If the company’s server goes offline, your website will be unavailable
If the company upgrades their software it might mean that some of the code used on your web site is incompatible. This can cause parts of your web site to ‘break’
URL stands for ‘Uniform Resource Locator’
There are many billions of web pages on the internet. There has to be a way of identifying every single one of them.
Each web site has a unique address such as www.google.com or www.teach-ict.com
This address is called the web page URL.
No other web site on the internet has the same address.
PROTOCOL - the set of rules which must be followed - websites use the HTTP and HTTPS protocols
DOMAIN OR DOMAIN NAME - the name of the server where the website is stored or hosted - this stands for the IP address of the server
PATH - the specific folder/files from the web server that you want to access
Why they are needed
IP addresses are hard to remember - words are easier
IP addresses identify the server that the website is saved on - IP addresses do not contain the protocol or the path
Many resources can be saved on the same host server - this means that they all have the same IP address. The protocol and path are needed to locate the specific resource on the server
DNS stands for Domain Name System.
The DNS is the internet’s equivalent of a phone book.
It acts as a directory of every domain name (e.g. www.bbc.co.uk) and its corresponding IP address.
This directory is actually a database.
The database is stored on a number of servers throughout the internet. They are called ‘Domain Name Servers’.
How it works
- You type a URL into your web browser.
- Your browser sends a request to a DNS server.
- It accesses the database on the DNS server and looks up the corresponding IP address for the website.
- The IP address is sent back over the internet to your web browser on your computer.
- The browser uses the IP address to locate the server hosting the website.
- It then sends a request to the host server, asking it to deliver a copy of the web page to your browser - the protocol and path are used to do this
- The host server sends a copy of the web page (broken into data packets) over the internet, back to your web browser.
- Your web browser reassembles the data packets and displays the web page on your screen.
Advantages of DNS
You do not need to remember any IP addresses of websites
So long as you are connected to a DNS server you can access any website for which there is a stored IP address
ISP stands for ‘Internet Service Provider’
An ISP is a company that provides you with access to the internet.
You might hear them referred to as an ‘internet provider’
ISPs normally charge a monthly fee for their service.
If you don’t pay the fee, or you cancel your contract, you won’t be able to use the internet (except in public Wi-Fi hotspots)
- BT internet
- Talk Talk
a protocol is a set of rules that nodes must follow in order to communicate on a network
The internet uses the TCP/IP protocol (Transmission Control Protocol/Internet Protocol)
This protocol enables every device on the internet to connect together.
Other protocols are used as well - it just depends on the task being carried out - web browsing, emailing, sharing files, streaming etc
Every hardware device (e.g. host servers, routers and workstations) connected to the internet has its own unique address.
This is called an IP address (short for Internet Protocol)
The IP address enables every device on the network to be identified and located.
The IP address is assigned by the ISP.
This is not the same as the MAC address which is assigned by the manufacturer of the hardware.
Internet Network type
The internet is a network of networks
It is a WAN - it covers most of the globe
Consists of lots of LANS and WANS which are linked together
Mainly client-server - host servers distribute resources to clients via the web server on their LAN network
Can use peer-to peer - internet users can set themselves up as peers so they can share resources (e.g. video and audio files) with other peers using software such as Bittorrent
Partial mesh - nodes are connected to lots of other nodes but each node is not connected to every single other node
The LANS and WANS that make up the internet may use other topologies such as star, but they are linked together with routers in a partial mesh formation
Access to websites - the World Wide Web (WWW)
Peer-to-peer (e.g. Bittorrent and the dark web)
Transferring files using FTP (file transfer protocol)
You can host a website on your own computer. This is called ‘local hosting’
If you plan to do this, you need to set your computer up as a web server.
This will enable people to connect to your computer to access the web site and any related files.