Transcript The INTERNET - Deyes High School

Year 11 Revision
THE INTERNET
The Internet
First used by the US Military in the 1970’s and known as
Arpanet.
The internet is made up of millions upon millions of small
computer networks all brought together to form the vast “
Inter-Network".
That word never caught on, so it was shortened to the much
easier-to-say "Internet".
A large part of the Internet is the 'World Wide Web" ( WWW).
The Internet isn’t just WWW!
ISP
ISP stands for 'Internet Service Provider'.
An ISP is a company that provides Internet access. For a
monthly fee they will offer you a broadband connection to the
Internet. Without this service, most businesses and
individuals would not be able to use the Internet.
Often, they provide other services as well such
as email, web site building and web site hosting.
Examples of ISPs are AOL, Tiscali,
BTBroadband, Sky, BeBroadband
Other ways of connecting to the internet:
Internet Ready TV’s
Smart Phones – via mobile phone
network
Navigating around the Web…
The internet is a massive resource of information so we need to
know how to find what we are looking for..
Search engines (such as Google) allow us to find things we are
interested in. Generally you search by using keywords which
the engine will link to sites it has stored in its database.
You can search for more than one keyword by using ‘And’ and
‘Or’ operators.
No single search engine has every website on it so it’s worth
using more than one.
If you know the web address already then you can just type in
the URL…
URL stands for Universal Resource Locator
http = Hypertext Transfer Protocol ( the language of the
Internet)
www = World Wide Web
bbc = The domain name (i.e. name of the company)
.co = Tells you it is a company
.uk = Tells you which country the site is based in
/news - is the actual page itself on the website
You can also navigate to different web pages via Hyperlinks..
These are parts of a website where you can click and go to a
different page – either an image or text.
Usually your pointer changes to a hand when hovering over a
link…
Or you can navigate to other pages by using..
Bookmarks, History, Page Tabs, and the Back and Forwards
buttons.
Shopping
Whatever you want to buy, you can pretty much guarantee that
you can find it for sale somewhere on the internet.
Leisure and Entertainment
There are many different ways that you can choose to spend
your time online and amuse yourself. Here are a few:
Playing online games
Listening to music
Reading online books
Watching online videos e.g. YouTube
Looking for holidays or concert tickets
Reading about your hobbies
Keeping up-to-date with the news and sporting events
User Generated Content
A large number of websites are based around content that
people who use the sites upload regularly.
Eg. Discussion Forums, Wikipedia, Social Networking
(MySpace), Blogs, File Sharing sites
Use of these sites creates an online ‘community’ with people
who have common interests.
Pros:
Can be fun and can provide useful information
Cons:
Can get too involved in the online world – anyone can put
anything on, Copyright?
Social Networking
Allows people to create their
own profiles just about them.
Lets users create their own ‘Communities’ linked to all their
friends accounts
Can communicate through email, posting messages on each
others message board or online chat
Can use webcams to video chat through the sites
Have the ability to add or remove friends who can see your profile
and interact with you.
Better than normal ‘Chat Rooms’ as you can control who can see
your profile and communicate with you!
Advantages of Social Networking
Networks can be world wide – and you can keep in contact with
people who move away from your local area
You can be creative on the internet with your own profile
Large Networks can raise awareness of important issues
Disadvantages
Privacy settings can be hard to understand and don’t always
work – so you could share too much information about yourself
Employers have sacked or not taken people on due to
information about that person they have found on the internet.
Benefits of the Internet
Always available
The Internet is always available for you to
use. You don't have to wait for it to open or
wait for someone to make it available. It is just
there, when you need it and for whatever you need.
Vast range of information
Think of any search term and type it into a search engine. We
can pretty much guarantee that you will find web sites with
information on that term.
It doesn't matter what you want to know about, you will find
something on the Internet that can provide the information
you need.
Easy to contact people
The Internet provides many ways to enable you to keep in
contact with people at all hours of the day and night. From
email, forums, chartrooms, telephone calls and video
conferencing. You are almost spoilt for choice.
This ability has helped many companies grow from a small
local company into a large, multi-national organisation.
Access to other cultures
The Internet enables you to look at sites about or written by
people in other countries. You can look at
photographs of where they live and read
about their way of life.
Issues with the Internet
Information overload
There is almost too much information on the Internet. It is easy to
feel overwhelmed by the amount of information that is out there.
Information can be biased
No one owns the Internet and there is nothing to stop people
posting their opinions and points of view on web pages, forums,
blogs.
Addiction
There has been a worrying increase in the number of people who
are becoming 'addicted' to the internet. Every spare moment they
have is spent online, some even go without proper sleep so that
they don't have to log off. There have been reports of families
breaking up and people losing their jobs because of this problem.
Information can be inaccurate
With an encyclopaedia, you can be confident that what you are
reading has been checked, cross referenced and is correct. But with
the Internet how do you know what has been written is correct?.
Offensive material
No matter how careful you are when using the Internet, there is
always the possibility that you will come across some sites that
contain offensive or even illegal material.
The police spend a lot of time trying to track down and shut sites
which have unsuitable images of children on them. But as soon as
they close one, another one pops up.
Almost anything that is illegal still exists on the internet somewhere!
Cyberbullying
With the growth of the Internet and new technology, bullying
has been moving from the traditional playground to emails,
chatrooms, texts and social websites.
This type of bullying is every bit as harmful and hurtful as if
done in person but it is much harder to tackle and stop.
Year 11 Revision
WEBSITE DESIGN
And
Data Security
Most websites are written in HTML
Hyper Text Markup Language
Most word-processing software can save documents in HTML
format.
In ‘the old days’ websites where built totally from code –
that’s why websites looked fairly basic in the 1990’s.
1994 – White House government website
2010 – White House government website
Static, Dynamic and Interactive?
Web pages can now be a combination of the three.
Static – Content just graphics, text and links – nothing ever
changed.
Dynamic – content is updated each time the page reloads/
refreshes. Such as the time or date – or your account on FB
showing new posts and updates.
Interactive – e.g. video and audio on websites – to be
interactive the user must have control of starting and
stopping it.
Getting your site online:
You need to things once you have built your website..
A Domain Name
Web Hosting
Domain Name – this is the address of your website eg
www.bbc.co.uk
You purchase the use of your domain from anyone of a
number of web companies – however you only ever Lease the
name (usually for 2 years) and then have to renew.
Web Hosting
Now you need to pay someone to host your website for you on
their Servers
The web site is loaded in a directory on the server's hard disk.
Then, whenever a request is made to view a web page from the
site, the server finds it on the hard disk and sends a copy to the
computer that made the request.
The 'World Wide Web' is
made up of millions of web
servers, each connected to
the Internet.
Web Security:
Data is very valuable (as valuable as money to some people)
We are most exposed financially when using online shopping
sites (Amazon, Ebay etc)
Some people are worried about giving their credit card or
bank details out on sites like these.
To protect us (and themselves) companies
use data encryption software.
When you put in your card or bank details the website converts
these into code using an algorithm (a program written
specifically to do this).
So instead of transmitting your card details via your phone line
to the store servers it sends the encoded details instead.
At the other end the receiving computers must have the same
piece of software (algorithm) and a ‘KEY’.
The ‘KEY’ is like a password which tells the system how to
decode the information.
In theory even if someone intercepts (steals) this data then they
won’t be able to access your bank details as they don’t have the
key.
Usernames and Passwords are also used by websites in an
effort to keep your password safe.
e.g. to log into your facebook account you need to type in
your email address and password.
Passwords are stored on the websites servers and are
matched against your username when you type your details
in – this tells the system who you are, if it is you and all the
data you are allowed to see.
However passwords are always being broken – you have to
be careful.
Hint: - for your password reminder – use a question only
you would know the answer to!!!
Hacking
A hacker is a person who breaks codes and passwords to gain
unauthorised entry to computer systems.
Hackers can do an enormous amount of damage if they break
into a computer system.
For some people, the challenge of breaking the codes is
irresistible and so precautions have to be taken.
Stand-alone computers are usually safe as there is no connection
for the hackers to break into. Computers which form part of
networks or those with external links, such as attached modems,
are in danger from hackers.
Many hackers often don't intend to cause damage or steal
data, they just enjoy the challenge of breaking into a
system.
However, in some instances the hacker's purpose could be
to commit fraud, to steal valuable data or to damage or
delete the data in order to harm the company.
Most hacking is carried out by employees with a grudge or
those who want to 'make some quick money'.
They have insider knowledge of passwords
and User IDs which makes it easy for them.
For a company being hacked into can have various
consequences, some of which can be seen below
For personal users it can be just as serious but for other
reasons!!
Physically protecting systems
Businesses can use a range of physical methods to protect
their systems and data.
Some of these include:
- Keeping important computers such as servers or
mainframes in locked rooms
- Posting security guards
- Security locks, smart cards
- Keeping sensitive data on stand-alone machines instead of
networks
- Using alarm systems and video cameras
Using software to protect systems
A business can also use software to help protect their systems.
Some of these methods include:
- Data encryption
- Firewalls - software to block access from outside (and to
prevent data being sent out in some cases)
- Activity or Audit logs - to track who has been doing what on
the system
- User IDs and Passwords
- Access rights