1.2.2 Applications Software

Question 1

How is applications software different to systems software?

Answer 1

Application software is utilised directly by the user
Systems software ensures the high performance of the computer

Question 2

Give 5 examples of utilities.

Answer 2

Compression
Disk defragmentation
Antivirus
Automatic backup
Automatic updating

Question 3

What is closed source software?

Answer 3

Software with source code that cannot be accessed by the public

Question 4

Give 3 advantages of using closed source software.

Answer 4

Regular, tested updates
Expert support & user manuals
High levels of security

Question 5

Give 2 disadvantages of using closed source software.

Answer 5

Often requires purchase of license
User cannot modify to their needs

Question 6

What is open source software?

Answer 6

Software with source code that can be used, changed and distributed by its users

Question 7

How is open source software often developed?

Answer 7

In a collaborative & public manner

Question 8

Give 3 advantages of using open source software.

Answer 8

Doesn’t require purchase of license
User can modify to their needs
Community of developers adapting and debugging code

Question 9

Give 2 disadvantages of using open source software.

Answer 9

No support
Compatibility issues with other software

Question 10

What is compiled code?

Answer 10

Code that is generally compiled and not interpreted

Question 11

What is interpreted code?

Answer 11

Code that is generally interpreted without compiling a program into machine instructions

Question 12

Give two advantages of using compiled code over interpreted code.

Answer 12

Faster execution
Does not require compiler

Question 13

Give two advantages of using interpreted code over compiled code.

Answer 13

Runs without time waiting for compilation
Useful for debugging

Question 14

What is assembly language?

Answer 14

A low level language with a near one-to-one relationship with machine code
Platform specific

Question 15

What is a low level language?

Answer 15

Languages close to actual machine instructions that aren’t human-readable

Question 16

Give 2 examples of low level language.

Answer 16

Machine code
Assembly language

Question 17

What is a high level language?

Answer 17

Languages used by programmers closer to human language than machine

Question 18

What is object code?

Answer 18

Machine code that computers can execute within the complete program

Question 19

What is machine code?

Answer 19

Binary code that can be executed directly by the CPU

Question 20

What is source code?

Answer 20

Human-readable text that guides a programs execution and is written in programming language

Question 21

Name 3 types of translator.

Answer 21

Compiler
Interpreter
Assembler

Question 22

What is the function of a compiler?

Answer 22

Convert high level language input into a lower level language at once

Question 23

What are the stages of compilation?

Answer 23

Lexical analysis
Syntax analysis
Code generation
Optimisation

Question 24

What happens during lexical analysis?

Answer 24

Input is read character by character Characters grouped into tokens

Question 25

What happens during syntax analysis?

Answer 25

Tokens are compared to rules of programming language Syntax errors are identified Symbol table updated with details Semantic analysis (logic errors)

Question 26

What happens during code generation?

Answer 26

Machine-readable object code or executable file generated

Question 27

What is the purpose of optimisation?

Answer 27

Reduce execution time Reduce inefficient sections of code Remove redundant code

Question 28

What is the function of an interpreter?

Answer 28

Convert high level language input into a lower level language line by line

Question 29

Give two disadvantage of using an interpreter.

Answer 29

Successful execution takes longer to complete Source code is needed every time

Question 30

How does an interpreter handle errors?

Answer 30

Stops execution until error on line is resolved

Question 31

What is the function of an assembler?

Answer 31

Convert programs written in assembly language into machine code

Question 32

What is the function of a linker?

Answer 32

Link external modules/libraries to main program

Question 33

Name the types of linkers.

Answer 33

Static Dynamic

Question 34

How does a static linker work?

Answer 34

Copies library code into file with compilation

Question 35

How does a dynamic linker work?

Answer 35

Address of libraries included within file

Question 36

Give two advantages of using dynamic over static linkers.

Answer 36

Doesn't increase file size External automatically feed through to main program

Question 37

Give two advantages of using static over dynamic linkers.

Answer 37

Faster execution Doesn't require external library

Question 38

What is a library?

Answer 38

Collection of pre-written code & subroutines

Question 39

Give three advantages of using libraries.

Answer 39

Error free Save time Re-usable

Question 40

What is the function of a loader?

Answer 40

Retrieves the library or subroutine from given memory location