I.C.T Revision 1

Page 1

Digital Data

Data is raw facts and figures which have not been processed and has no contexts. For example 234.

Information is data which has been processed and given context. For example 234 number of pupils in year 11.

bit 0 or 1

nibble 4 bits

byte 8 bits

kilobyte 1024 bytes

megabyte 1024 kilobytes

gigabyte 1024 megabytes

terabyte 1024 gigabytes

integers - whole number - 12, 1324, -34

real numbers - any number - 1.32, 4, -65

date and time data - format depends on setup - 23/06/2004, 11am, 15:00

character - letters digits spaces or punctuation - ? a 2 ! £

string - list of characters - "hello world!!"

currency - real numbers formatted a specific way - £12.45 $9999

alphanumeric (text) data - data made up of letters and numbers symbols and spaces are normally aloud -ABC123

Boolean (logical) data - can only have two values - true false yes no on off

Page 2

Representing Images

a pixel is the smallest image hat can be displayed on a computer screen. pixels are stored as bits

image resolution tells quality of an image. the greater the number of pixels used in an image the higher the resolution.

bitmap graphics are made up of a grid of pixels.