7. Classifications of Software

Question 1

Application Software

Answer 1

Can be general purpose, special purpose or bespoke.

Usually it is a piece of software meant to deal with a task relevant to real life events such as entertainment or handle real tasks.

Question 2

General Purpose Software

Answer 2

e.g. Word processor, Graphics Package.

Can be used for many different purposes.
Cheaper than special purpose software (duh.)
Tend to have less bugs as they could be open-source or have more users as it fits a general criteria.

Question 3

Special Purpose Software

Answer 3

Performs a specific task e.g. Payroll, accounts package, hotel booking systems.

Can be bought ‘off shelf’ or bespoken. Ready made almost always cheaper than commissioning bespoke software.

Question 4

Systems Software

Answer 4

Performs the tasks needed to operate the hardware

Question 5

Utility Programs

Answer 5

System software designed to optimise the performance of the computer or performance tasks.

e.g. Disk Defrag software, anti-virus, firewall, backing up files, compressing data.

Question 6

Library Programs

Answer 6

Collection of programs that do specific jobs.
Programmers can call and use these in their programs.

e.g. A printing routine can be used by a word processor and a spreadsheet program.

Question 7

Machine Code

Answer 7

This is the code that can be directly executed by the computer.

e.g. 101100001011

Question 8

Assembly Language

Answer 8

Low level language

Same structure/instruction as machine code but used mnemonics instead of numbers.
e.g. Mov A,B

Pros:

• Occupies little space
• Executes almost as fast as machine code

Question 9

High Level Languages

Answer 9

Are languages with strong abstraction from the details of the computer. Allows for programming to be much easier and understandable than low level languages.

e.g. Python, C++, C#, Pascal, VB

Question 10

High Level Languages vs. Low Level Languages

Answer 10

HLL are simple to understand for programmers, easy to: debug, maintain and they can be portable like C++.

LLL, can optimise performance or use of hardware ie more memory effecient however it is machine-dependent.

Question 11

Assemblers

Answer 11

Translates an assembly language program into machine code.

Question 12

Compilers

Answer 12

Scans the whole code and translates it all into machine code.
No translation takes place when running, so it is much faster.
No extra software required.
Errors only show after compilation, may be tedious, not preffered for debugging.

Question 13

Interpreters

Answer 13

Executes each line of high-level language as they come up one by one.
Breaks once it reaches an error.
Useful for program development as there is no need to recompile code after editing the code.

Question 14

What is the relationship between Assembly Language and Machine Code?

Answer 14

They’re 1:1, assembly language is just machine code expressed in mnemonics.

Question 15

Translators

Answer 15

A program that converts code from one language to equivalent code in another language

All code needs to be translated to machine code in order to execute

Question 16

Name the 3 Translators

Answer 16

Interpreter
Compiler
Assembler

Question 17

Bytecode

Answer 17

Program code that has been compiled from source code into low-level code for a software interpreter.
It may be executed by a virtual machine (such as a JVM) or further compiled into machine code, which is recognized by the processor.

Question 18

Bytecode Contextualised

Answer 18

Java programs are usually compiled into byte code and are interpreted at run time by a Java Virtual Machine. This makes Java platform independent i.e. will run on different machines and platforms provided there is a JVM written for that hardware/operating system combination.

Question 19

Object code

Answer 19

Object code is the product of a compiler. The term indicates that the code is the goal or result of the compiling process.