Data, Information and Knowledge
Data is any word, number, letter, image, sound etc with no context. Data is processed by computers.
Information is a collection of data put into context, giving them meaning.
A structure is needed in order for data to become information. e.g. In a table without headings, the data in them have no meaning. If headings are added, then it has some meaning and is therefore information.
Databases and spread sheets have structure with headings so they often turn data into information.
Data can be collected manually or input devices can collect data automatically e.g. sensors that continually measure a temperature or a fix-mount barcode reader at a till.
Knowledge is the ability to understand information and to then form judgements, opinions, make predictions and decisions based on that understanding.
So, information can be used to make predictions and understandings, so information can become knowledge.
Data Transfer - from one application to another
Data transfer is the transfer of data files containing images (graphics), text, sound etc from either one hardware to another or one application to another. This is possible because standard file types and data formats have been developed.
From one application to another:
Data can be stored temporarily in a computer's RAM as a means of transfer from one application to another. In Microsoft operating systems this feature is called the clipboard and it can copy data from one application and paste it into another. Nearly all other operating systems support this functionality.
For example you can create a graph using a spread sheet application and then use the clipboard to copy the graph to a desktop publishing application.
1. Certain elements of one document may not be able to be copied to another application, e.g. video.
2. Some file features (e.g. text layout and formatting) may be lost in the translation to a different format.
Data Transfer - import and export
Most applications have the ability to import and export data. Export saves the file in a format that's readable by other applications. Import opens a file created in another application for viewing or editing.
Standard File Types: Data files are stored in a number of formats, the formats depend on which application created the file to begin with. For example, Microsoft Word stores files as *.doc but Adobe Photoshop stores files in a different format - *.psd. The file extension identifies the file's format. When data is transferred from one computer to another, the computer receiving the data file may not be able to read the format without the right application installed. For example, an image created in Adobe Photoshop and saved as a *.psd file (Photoshop's format) would not be readable by Microsoft Paint. The need to import and export data files has led to the development of several standard file types that many applications can understand. Often an application of a different type can import data, for example, a word processor may be able to import a spreadsheet file. Examples: mp3, gif, jpg, xml files, zip & pdf: compressing it using zip technology or making it possible to read using a freely available downloaded reader application, as is the case with PDF files.
Other transfer of files
Files can be easily transferred and shared across the globe using the Internet. A file could be:
-Emailed as an attachment.
-Sent over instant messenger.
-Downloaded from a website/webserver.
-Accessed over a private network.
Documents e.g. spread sheets can be stored on a web server and then accessed via any computer with an Internet Connection and a web browser.
Other methods of data transfer include:
USB sticks storing data and then transferring this data onto computers by plugging them into the USB port. Bluetooth to transfer media files like music, images and videos from one device to another. Infra-red to transfer media files from one device to another. Firewire used to transfer files.
Data Security - key threats
Data can be...
-Lost or damaged during a system crash – especially one on the hard disk.
-Corrupted as a result of faulty disks, disk drives or power failures.
-Lost by accidentally deleting or overwriting files.
-Lost or become corrupted by computer viruses.
-Hacked into by unauthorised users and deleted or altered.
-Destroyed by natural disasters, terrorism or war.
-Deleted or altered by untrustworthy employees seeking revenge on the employer.
Data Security - keeping data safe
Data can be kept safe by...
-Making regular backups of files (backup copies should be stored in fireproof safes or in another building).
-Protecting yourself against viruses by running anti-virus software
-Using a system of passwords so that access to data is restricted.
-Safe storage of important files stored on removable disks, eg locked away in a fireproof and waterproof safe.
-Allowing only authorised staff into certain computer areas, eg by controlling entry to these areas by means of ID cards or magnetic swipe cards.
-Always logging off or turning terminals off and if possible locking them.
-Avoiding accidental deletion of files by write-protecting disks.
-Using data encryption techniques to code data so that it makes no apparent sense.
When you bank online, after you’ve logged in, you will notice that the http in the address bar has changed to https. This indicates that a secure connection between your computer and the bank's computer has been established. Data sent between the two computers is encrypted so that anyone trying to intercept your data will receive meaningless data. The data can only be decrypted into readable data by using a key that is known only to the two computers - yours and the bank's.