Unit 2

E-commerce: buying and selling goods and services over the internet.

Requirements needed for an E-commerce system:

• Trained staff to create and maintain website
• An electronic catalogue of stock so they can see if product is in stock or not
• Method of secure payment / shopping trolley - for safe payments for customers
• Order/ email confirmation of purchases

Advantages to customer:

• Disabled people can do more shopping at home
  
• Able to compare differnet websites to find cheapest goods
• Availalble to order goods 24/7
• Deals/ Discounts available online
  
• Greater choice of goods from a global marketplace
  
• No travelling goods are ordered online saves cost and time

Disadvantages to the customer:

• Problems with fraudulent sites / fake sites
  
• Hidden cost of postage
• Hard to assess quality before purchasing
• Security of credit cards
  

Advantages to the business:

• Online catalogue is easily updated / Fewer staff needed
  
• Low start up and running costs
• Global marketplace reaches lots of customers worldwide
  

Disadvantages to the business:

• Network downtime can be expensive
• Incresed competition with other companies
• Reliance on third party delivery companies

Where a series of computers are networked together and work on solving same problem.
Sharing the same data processing project between different computers on the network.

Universities and reasearch labs use this by combining the power of several small computers instead of using a supercomputer. Small tasks assigned to each comptuer.
Used for helping to develop flu vaccines because the flu may be complex and therefore simulations needed to model the human immune system & show how different viruses affect

Advantages:

• Reduces costs because no supercomputers needed.
• Can pass data to any part of the world using the internet.
  
• Improved performance as each computer works on differnet part of data. 

Disadvantages:

• There are issues with security because data is spread out.
• Increased cost owing to the use of expensive communication lines
  

The SETI Project: (Search for Extra-Terrestrial Intelligene)

• Looks for intelligent life outside Earth
• Uses radio telescopes to pick up signals
• Signals from out of space are very complex

At first supercomputers containing parallel processors were used to process the mass data produced fro the telescopes. 

Then someone thought of virtual supercomputer processing consisitng of huge number of internet connected computers combining power.

FTP: is a standard set of rules that have been established to allow the exchange of large files over the internet.

• A package of data is sent
• When recieved the system checks to make sure no errors had occured during transmission
• Message is sent back to sender to let them know package is OK and next one is sent.

FTP is used by: companies to distribute information between businesses and other organisations such as their suppliers and customers.

Used to uploading a database of sales from one branch to the head office.
Used for downloading or uploading a website to the internet.

Advantage:

• Rather than attaching files to emails for transfer you can use FTP which does not limit the file size at all. Therefore you can transfer large files.

Dialup Modem:

• Very slow and also limits use - downloads can take an hour not a few minutes
• Converts digital signals into sounds which are passed along a telephone line.
  
• The sound is converted back to digital signal so computer understands.

Broadband:

• Faster access and transfer sppeds to the internet which allows you to do things quicker.

Advantages:

• Fast download times / Can listen and watch TV in real time
• Does NOT tie up the phone line
  
• Search engines work faster / no time wasted connecting to internet

Disadvantages:

• Expensive because high monthly subscription / broadband not available everywhere.
  

Moral Issues:

• Deliberately setting up website containing the wrong information
• People bullying in online chat rooms & Spreading rumours
• Innapropriate websites - able to view violence, racism and ***********

Ethical Issues:

• Plagariasm -copying material without referencing the source of information
• Sending spam -people waste time deleting spam if the spam filter allows it still
• Using photo editing software to distort reality - can no longer believe what you see.

Social Issues:

• Privacy Issues - social networking, e-commerce sites and email monitoring - intruding privacy
• Obesity - many acitivites in the past involved physical excercise which kept people healthy
  
• Gambling Addiction -gambling can cause many social problems and its on the rise as bets can be made using the internet.

Constantly being modified and updated.

E-commerce systems make use of them to keep details of their customers and products.

EDI  - Electronic Data Interchange - where companies automatically exchange data used by retailers to order goods from their suppliers.

How to access online information?

URL (Uniform Resource Locator) -  The web address of a site entered on the WWW - the recognised method of referring to resources on the internet.

Surf the internet following hyperlinks -  using hyperlinks to move from one area of interest to another. hypertext is underlined or in another colour.

Search Engines -  an application accessed over the internet that maintains indexes of web pages and logical key words to find the information required.

Before a search engine can find information it needs to store information on pages such as web crawlers/ web browsers / web spiders.

These automatically follow all links it can find and adds them to an index. The index is stored in a database. The search engine then performs a search within the index and the index is examined and any webpages which contain the words are suggested.

Web Crawler -continually searches the web looking for new pages and recording information they find. Which browses the web and keeps an index of what it finds. Orders them according to:

• Relevance to the search criteria
• Most popular sites
• Authorative sites

A search using the operators AND, OR or NOT.

AND:
narrows a search by combining terms. It will retrieve documents that use both the search terms you specify. e.g. Portland AND Oregon

OR:
broadens a search to include results that contain either of the words you type in e.g. liberal OR democrat.

NOT:
will narrow a search by excluding certain search terms e.g. France NOT Canada.

If you want an EXACT MATCH if words then put quotation marks around the words like 'Recipe for chocolate chip cookie'.

Boolean Searches allow you to combine words and phrases using the words and phrases using the words AND, OR, NOT and NEAR to limit, widen or define your search.