Chapter 3: Part 2

Question 1

What is the difference between applications and
systems software?

Answer 1

Applications software is utilised directly
by the end-user whereas systems
software ensures the high performance
of the computer.

Question 2

Give 3 examples of utilities

Answer 2

Three from
- Compression
- Disk defragmentation
- Antivirus
- Automatic backup
- Automatic updating
- Encryption software

Question 3

Give one advantage of using closed source code

Answer 3

• Thorough, regular and well-tested updates
• Expert support and user manuals from company
• High levels of security as it is developed in a professional,
  controlled environment

Question 4

State two features of open source code

Answer 4

• Does not require a license to be used
• Distributed with the source code
• Can be modified and sold on

Question 5

Give two advantages of using compiled code over
interpreted code

Answer 5

• Faster to execute
• Does not require compiler to run

Question 6

Give two advantages of using interpreted
code over compiled code

Answer 6

Two from:
- Is platform independent
- Runs instantly without time waiting for compilation
- Useful for debugging

Question 7

What is assembly language?

Answer 7

A low-level language that has almost a
one-to-one relationship with machine
code. It is platform specific.

Question 8

What are the stages of compilation?

Answer 8

● Lexical analysis
● Syntax analysis
● Code generation
● Optimisation

Question 9

What happens during syntax analysis?

Answer 9

-Parsning: Tokens are compared to the rules of the
programming language
- Syntax errors are identified
- Symbol table updated with more details
- Semantic analysis (finding logic errors)
- Syntax Tree created

Question 10

What are the similarities and differences between
static and dynamic linkers?

Answer 10

Similarities: Both link external modules and libraries to main
program
Static: Library code copied into the file. File size increased.
Dynamic: Addresses of libraries included within file. External
updates automatically feed through to main program.

Question 11

Give three advantages of using libraries.

Answer 11

• Error-free
• Save time
• Re-usable
• No need to ‘reinvent the wheel’
• Designed by experts

Question 12

Describe the function of a loader

Answer 12

Provided by the operating system, a loader
retrieves the library or subroutine from the given
memory location.

Question 13

What is the purpose of the optimisation stage of
compilation?

Answer 13

● Reduce execution time
● Reduce inefficient sections of code
● Remove redundant code