1.2.2

Question 1

What is applications software?

Answer 1

Software which is designed to be used by the end user to perform a task

Question 2

What are some examples of applications software?

Answer 2

• word processor
• web browser
• spreadsheet software

Question 3

What is systems software?

Answer 3

Software which is responsible for the smooth running of a computer, interacting with hardware devices and generally providing a platform for applications software to run

Question 4

What are some examples of systems software?

Answer 4

• OS
• device drivers
• utility programs

Question 5

What is utility software?

Answer 5

Software which maintains consistent, high performance of the computer by completing maintenance tasks

Question 6

What are some examples of utility software?

Answer 6

• compression
• disk defragmentation
• encryption
• antivirus
• backup
• automatic updatint

Question 7

What is source code?

Answer 7

The code written by the programmer before it has been compiled

Question 8

What is open source software?

Answer 8

Software which can be used by anyone without a licence and users have access to the source code

Question 9

What is closed source software?

Answer 9

Users must have an appropriate licence to use the software and they do not have access to the source code

Question 10

What are the advantages of open source software?

Answer 10

• anyone can modify and improve software
• tech in cal support provided by online community
• can be modified and sold on

Question 11

What are the disadvantages of open source software?

Answer 11

• less secure
• online support may be insufficient

Question 12

What are the advantages of closed source software?

Answer 12

• secure
• regular, thorough, well-tested updates
• expert support provided

Question 13

What are the disadvantages of closed source software?

Answer 13

• users cannot modify/improve software
• number of users that can access software is limited

Question 14

What is a translator?

Answer 14

A program that converts high-level source code into low-level object code

Question 15

What are the three types of translator?

Answer 15

• compiler
• assembler
• interpreter

Question 16

What is the compiler?

Answer 16

A program that converts high level code to machine code all at once

Question 17

What are the advantages of using a compiler?

Answer 17

• can be run without a translator present
• all errors picked up at start

Question 18

What are the disadvantages of using a compiler?

Answer 18

• initial compilation process slow
• specific to OS/ processor

Question 19

What is an interpreter?

Answer 19

A program that translates and executes source code to machine code line by line

Question 20

What are the advantages of using an interpreter?

Answer 20

• not OS/ processor specific

Question 21

What are the disadvantages of using an interpreter?

Answer 21

• slower to run
• requires an interpreter to run

Question 22

What is an assembler?

Answer 22

A program that translates assembly code to machine code

Question 23

What are the 4 stages of compilation?

Answer 23

• lexical analysis
• syntax analysis
• code generation
• code optimisation

Question 24

What happens during lexical analysis?

Answer 24

• all white space and comments are removed
• all keywords/variable names are replaced with tokens
• tokens put into symbol table

Question 25

What happens during syntax analysis?

Answer 25

- the tokens are checked agains the grammar rules of the language - anything that breaks rules is flagged up - abstract syntax tree is created

Question 26

What happens during code generation?

Answer 26

- machine code produced using abstract syntax tree

Question 27

What happens during code optimisation?

Answer 27

- code checked for any areas which can be made more efficient - redundant code removed

Question 28

What are linkers?

Answer 28

A piece of software which links external modules and libraries included in the code

Question 29

What are static linkers?

Answer 29

The modules and libraries are added directly into the main file

Question 30

What are dynamic linkers?

Answer 30

The address of the modules and libraries are referenced in the main file

Question 31

What is a loader?

Answer 31

A piece of code which retrieves the library or module from the given memory location

Question 32

Why do we use libraries?

Answer 32

- they are error free - readily compiled - save time - ready to use - don’t need to reinvent the wheel