File Sharing

What is it?

File sharing is the practice of distributing or providing access to digitally stored information, such as computer programs, multimedia, documents, or electronic books. Common methods of storage and dispersion include manual sharing utilizing removable media, Web-based hyperlinked documents, and the use of distributed peer-to-peer networking.


Peer-to-peer file sharing

Users can use software that connects in to a peer-to-peer network to search for shared files on the computers of other users connected to the network. Files of interest can then be downloaded directly from other users on the network. Typically, large files are broken down into smaller chunks, which may be obtained from multiple peers and then reassembled by the downloader. 

Disadvantages of file sharing

• Security Problems- explicit programming required

• Integrity Problems- rules needed to be programmed explicitly

• Concurrent access anomalies- multiple access of same file in case of multiple user system 

• Data Isolation- related data required by different programs of same application may resides in diff isolated files 

• Unanticipated queries- handling sudden queries can be difficult 

• Data redundancy 

• Data inconsistency 

• Duplication of data 

•  No standardized control over organization of files 

• No standardized control over structure of files

Advantages of file sharing

• The downloading of files is fast and can cope with multiple downloads at once
• Easy to install and configure on computers within a network
• All the resources and content is owned by all the peers
• Unlike a Server - Client network, failure of one peer doesn't affect the functioning of other peers
• The over-all cost of building and maintaining this type of network is comparatively very less.
  

Social Networking

Fun facts and slightly serious thinking.

Many people rely on social networking to communicate to others on-line. So many people use this that there was a recent study that stated over 700 million people across the globe have a profile on a social networking site.

Facebook is by far the most popular means of interaction. Well recognised as the "original" social networking website, users can update their status, instant message friends, like pages and post photos. Although the site does offer a significant lack of freedom of customisation as the only things you can edit on your profile is your "cover photo" and profile picture. None the less the site has over 750,000,000 visitors a month and counting with over 400million unique users today.

Twitter is another popular social networking site. Although there is limited messaging capabilities and the fact you have to fit "what you are feeling or doing" into 150 characters, hasn't stopped the huge increase in users in the past year.  The site has over 250,000,000 visitors a month with over 80million unique users today. 

YouTube is 'the' most popular video sharing site on the internet with individual video views reaching well into the millions. Users can upload videos, comment, like and respond to other videos. Everytime a user or guest watches a video the 'view' counter tracks who has viewed the video. Many users who have applied to be partners of YouTube can now recieve money in return for displaying ads in their videos or on their individual channel. The site has over 490 million unique users each month.

Sources: http://mashable.com/2011/02/19/youtube-facts/

              http://www.ebizmba.com/articles/social-networking-websites

Stefan F. Meyer, 2012

On-line Services

What are they?

On-line services provide an infrastructure in which subscribers can communicate with one another. They can do this either by exchanging e-mail messages or by participating in on-line forums. In addition, the service can connect users with an unlimited source of information.
Subscribers can get up-to-date stock quotes, news stories hot off the wire, articles from many magazines and journals, in fact, almost any information that has been put in electronic form.


The difference between an on-line service and a bulletin board service is one of scale and profits. Online services provide a variety of information and services, whereas BBS's normally concentrate on a single theme.

• Three of the largest on-line services are America Online, Compuserve and MSN.

One on-line service that defies classification is the Internet. In terms of users, it is the largest service, but it is not centrally controlled by any one organization, nor is it operated for profit.





Stefan Meyer