1.2.2 Apps Generation Flashcards
Define utility software
System software with a specific purpose usually related to maintenance, which ensure consistent and high performance.
Give examples of utility software.
Compression
Disk defragmentation
Antivirus
Backup
Explain the need for disk defragmentation.
As hard disk fills, read/write slows down. Files become fragmented as they are stored in different parts of memory.
Defrag rearranges the contents so they can be accessed faster, improving performance.
Define open source software
Does not require a license to use
Source code can be viewed, modified and redistributed
Define closed source software.
Requires the user to hold an appropriate license to use it. Users cannot access the source code as the company owns the copyright license.
Advantages of open source.
Can be modified and improved by anyone.
Technical support from online community
Can be modified and sold on.
Advantages of closed source.
Thorough, regular and well tested updates.
Company owning software provides expert support and user manuals.
High levels of security as developed professionally.
Disadvantages of open source.
Support available online may be insufficient or incorrect. No user manuals
Lower security as may not be developed in a controlled environment.
Disadvantages of closed source.
License restricts how many people can use the software at once
Users cannot modify and improve software themselves
What should a user consider when deciding between open and closed source?
Costs (implementation, maintenance, training of staff, license)
Functionality (features available, ease of use)
What is a translator?
Program that converts high-level source code into low-level object code.
What are the three types of translator?
Compiler, interpreter, assembler.
What is a compiler?
Program that translates high level code into machine code all at once, after carrying out a number of checks and reporting back any errors.
What are the disadvantages of a compiler?
Takes much longer to translate the code than a interpreter or assembler.
If changes need to be made, the whole program must be recompiled.
Compiled code is specific to a particular processor type and operating system
What is good about a compiler?
Code can be run without a translator being present.
What is an interpreter?
Program that translates and executes code line-by-line. They stop and produce an error if a line contains an error.
Why is running interpreted code slower than running compiled code?
Code must be translated each time it has been executed.
What is useful about the line-by-line execution of interpreters?
It can be used for testing sections of code and pinpointing errors, as time is not wasted compiling the entire program before it has been fully debugged.
What does interpreted code require to run on different devices?
An interpreter.
Why is interpreted code more portable?
It can be executed on a range of platforms as long as the right interpreter is available.
Why is assembly code considered a low level language?
It is the next level up from machine code.
Why is assembly code platform specific?
The instructions used are dependent on the instruction set of the processor.
What do assemblers do?
They translate assembly code into machine code.
What is each line of assembly code roughly equal to?
Almost one line of machine code.
