1.1 The ability to transfer data from one system or software
application to anoter without having to re-enter the data.
2 Data Compresion
2.1 Data Compression is used to
reduce the size of a digital file.
2.2 It allows faster file uploads, downloads and
takes less time to attach files to emails.
2.3 Takes up less storage space
on a computer system.
3 Software Compression
3.1 Data files can be compressed by saving
them using a particular file format.
3.1.1 Graphics can be compressed
using JPEG or GIF format.
3.1.2 Music files can be
compressed to MP3 format.
3.1.3 Video files can be
compressed using MPEG.
3.2 WinZip is an example of
3.2.1 Files must be decompressed/unzipped/extracted
before they can be opened after compression.
4 The Purpose of a Check Digit
4.1 What is a Check Digit?
4.1.1 A digit added to the end of a code. The code is used in a
calculation and th check digit is recalculated. If the results
of the calculation do not match the check digit, and error
message appears. The code will have to be input again.
4.2 Where are they found?
4.2.1 On the ISBN on the back of a book.
4.2.2 At the end of a Univeral Product Code (UPC) or barcode on items in a supermarket.