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 examples of utilities.

Answer 2

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

Question 3

What are the advantages of using closed source code?

Answer 3

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

Question 4

What are some 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 a complier to run.

Question 6

Give some advantages of using interpreted code over complied code.

Answer 6

• 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

Both: Link external modules and libraries to the main program.

Static: Library code copied into the file. File size increased.

Dynamic: Addresses of libraries included within the file. External updates automatically feed through to the main program.

Question 11

What are some 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.