1.2.2 Applications Software Flashcards
How is applications software different to systems software?
Application software is utilised directly by the user
Systems software ensures the high performance of the computer
Give 5 examples of utilities.
Compression
Disk defragmentation
Antivirus
Automatic backup
Automatic updating
What is closed source software?
Software with source code that cannot be accessed by the public
Give 3 advantages of using closed source software.
Regular, tested updates
Expert support & user manuals
High levels of security
Give 2 disadvantages of using closed source software.
Often requires purchase of license
User cannot modify to their needs
What is open source software?
Software with source code that can be used, changed and distributed by its users
How is open source software often developed?
In a collaborative & public manner
Give 3 advantages of using open source software.
Doesn’t require purchase of license
User can modify to their needs
Community of developers adapting and debugging code
Give 2 disadvantages of using open source software.
No support
Compatibility issues with other software
What is compiled code?
Code that is generally compiled and not interpreted
What is interpreted code?
Code that is generally interpreted without compiling a program into machine instructions
Give two advantages of using compiled code over interpreted code.
Faster execution
Does not require compiler
Give two advantages of using interpreted code over compiled code.
Runs without time waiting for compilation
Useful for debugging
What is assembly language?
A low level language with a near one-to-one relationship with machine code
Platform specific
What is a low level language?
Languages close to actual machine instructions that aren’t human-readable
Give 2 examples of low level language.
Machine code
Assembly language
What is a high level language?
Languages used by programmers closer to human language than machine
What is object code?
Machine code that computers can execute within the complete program
What is machine code?
Binary code that can be executed directly by the CPU
What is source code?
Human-readable text that guides a programs execution and is written in programming language
Name 3 types of translator.
Compiler
Interpreter
Assembler
What is the function of a compiler?
Convert high level language input into a lower level language at once
What are the stages of compilation?
Lexical analysis
Syntax analysis
Code generation
Optimisation
What happens during lexical analysis?
Input is read character by character Characters grouped into tokens
What happens during syntax analysis?
Tokens are compared to rules of programming language
Syntax errors are identified
Symbol table updated with details
Semantic analysis (logic errors)
What happens during code generation?
Machine-readable object code or executable file generated
What is the purpose of optimisation?
Reduce execution time
Reduce inefficient sections of code
Remove redundant code
What is the function of an interpreter?
Convert high level language input into a lower level language line by line
Give two disadvantage of using an interpreter.
Successful execution takes longer to complete
Source code is needed every time
How does an interpreter handle errors?
Stops execution until error on line is resolved
What is the function of an assembler?
Convert programs written in assembly language into machine code
What is the function of a linker?
Link external modules/libraries to main program
Name the types of linkers.
Static
Dynamic
How does a static linker work?
Copies library code into file with compilation
How does a dynamic linker work?
Address of libraries included within file
Give two advantages of using dynamic over static linkers.
Doesn’t increase file size
External automatically feed through to main program
Give two advantages of using static over dynamic linkers.
Faster execution
Doesn’t require external library
What is a library?
Collection of pre-written code & subroutines
Give three advantages of using libraries.
Error free
Save time
Re-usable
What is the function of a loader?
Retrieves the library or subroutine from given memory location
