2.1 Binary - Base 2 number
system, used by computers,
uses the digits 1 & 0 only.
2.2 Denary - Base 10
how we normally
count, uses digits 0
2.3 Hexadecimal (Hex) - Base
16 number system used by
humans to represent groups
of four bits at a time. Uses
digits 0 to F.
2.4 Overflow - When the result of a
numeric calculation is too large to be
stored in the space reserved for that
type of data.
3.1 Character set - The set of symbols that can be
represented by a computer. The symbols are
called characters and can be letters, digits,
space, punctuation marks and some control
characters such as “escape”. Each character is
represented by a numerical code that is stored
as a binary integer.
3.2 ASCII - American Standard Code
for Information Interchange: a
7-bit character set used by PCs.
(There is also an extended ASCII
character set that uses 8 bits.)
3.3 EBCDIC - Extended Binary Coded
Decimal Interchange Code: an 8-bit
character set used by older mainframes.
3.4 Unicode - A 16-bit
character set that
allows many more
characters to be
4.1 Bitmap image - An image that has been
stored as a series of values per pixel. The
colour of each individual pixel is stored in
4.2 Vector Graphic - An image file that is made
up of lines and shapes that have certain
properties, for example, a line may have the
following properties: start- point, end-point,
line colour, line thickness, line style. The
properties of each shape are stored in a file
to make up the image.
4.3 Pixel - Short for picture
element. It is the smallest
component of a
4.4 Colour depth - The number of bits used to
represent the colour of a single pixel in a
bitmapped image. Higher colour depth gives
a broader range of distinct colours. For
example, an image stored as a .gif file uses 8
bits per pixel so the image could use 256
4.5 Resolution - The number of pixels in an image
expressed as: the-number-of-pixels-across x
the-number-of-pixels-down eg: 400 x 600.
4.6 Metadeta - Data about data. In the
case of image files metadata is the
data the computer needs to interpret
the image data in the file, for example:
resolution, colour depth and image
5.1 Analogue - A
wave such as
5.2 Digital - Data that is made up of
separate values. How data is stored
on a computer.
5.3 Sample rate - The number of times per
second that the sound wave is measured.
The higher the rate the more accurately
the sound wave is represented.
5.4 Sample interval - The time gap
between measurements of the
sound wave being taken.
Another way of expressing the
5.5 Sample resolution - The number of bits
used to store the value of each sample.
The higher the number of bits the more
accurately the value is stored.
5.6 ADC - Analogue to Digital
converter: takes real-world analogue
data and converts it to a binary
representation that can be stored
on a computer.
6 Data and information
6.1 Data - Facts and figures
with no context or format
to give them meaning.
6.2 Information -
Processed data that
has context and
format so that it
7.1 Instruction set - The group of instructions available for
that specific processor to use. The number of
instructions available will depend on the number of bits
used. For example, with 4 bits there could potentially be
15 different instructions.
7.2 OP Code - The group of bits in an
instruction that represents the
operation such as EAT, MOVE or
7.3 Compiler - A piece of systems software that
converts a program written in a high level
programming language into machine code
7.4 Machine code - A binary
representation of a program.
7.5 High Level Programming Language - A programming
language written in constructs using language we can
understand. Languages include Delphi, Visual Basic,
Java and C++.