1.2.2. Applications Software

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

• Compression
• Disk defragmentation
• Antivirus
• Automatic backup
• Automatic updating

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

• 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)

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