application stuff

Question 1

software categories

Answer 1

systems, applications

Question 2

systems software

Answer 2

needed to control hardware and run applications

Question 3

system software - types

Answer 3

operating systems, utilities, libraries, translators

Question 4

operating system

Answer 4

provide a user interface, manage hardware, handle interrupts, schedule processor

Question 5

utility programs

Answer 5

optimise computer performance and perform useful background tasks

Question 6

utility programs - examples

Answer 6

disk defragmenter, automatic backup, automatic updating, virus checker, compression software

Question 7

disk defragmenter

Answer 7

reorganises the hard drive so parts of the same file are next to each other in sequential blocks to reduce read times

Question 8

automatic backup

Answer 8

accounts for users forgetting to backup files by automatically doing it if where, when, how (compressed or not) and what (data) is to be backed up are specified

Question 9

automatic updates

Answer 9

runs in the background detecting and automatically installing software update releases

Question 10

virus checker

Answer 10

scans permanent storage by comparing files to know virus definitions and/or using heuristics to guess which files may contain a virus based on their behaviour

Question 11

compression

Answer 11

reduces file size to increase transmission speeds or increase the number of files that can be stored in a given storage capacity

Question 12

application software

Answer 12

software that performs a task to benefit the user

Question 13

off the shelf software

Answer 13

ready made software that is available for anyone to purchase

Question 14

bespoke software

Answer 14

custom software created for a specific user

Question 15

off the shelf software - advantages

Answer 15

cheaper, consumer can try/read reviews

Question 16

bespoke software - advantages

Answer 16

allows specific features to be included for the user

Question 17

open source software

Answer 17

software is open source licensed but free to use, source code is free to view, modify, distribute and sell as long as the software produced is also open source

Question 18

freeware

Answer 18

software is free to use but software ins’t available

Question 19

closed source/proprietary

Answer 19

source code is not freely available, user must pay copyright owner for a license to use the software which may restrict how the software can be used

Question 20

selecting application

Answer 20

functionality, hardware, cost, availability, reliability

Question 21

assembly code

Answer 21

three letter acronyms are used to represent instructions which are equivalent to binary instructions but easier for humans to work with (hardware specific)

Question 22

assembler

Answer 22

translates assembly to machine code

Question 23

compiler

Answer 23

translates high level languages to machine code in one go

Question 24

interpreter

Answer 24

translates high level languages to machine code line by line, stopping if there’s an error

Question 25

compiler - advantages

Answer 25

programs can be rerun without needing to be recompiled, faster to execute, executable file doesn't require interpreter to run

Question 26

interpreter - advantages

Answer 26

source code can be run on any machine with the interpreter, the entire program doesn't need to be recompiled if a small error occurs

Question 27

compiler - disadvantages

Answer 27

code must be recompiled if a small error occurs

Question 28

interpreter - disadvantages

Answer 28

must be reinterpreted each time the program is run

Question 29

stages of compilation

Answer 29

lexical analysis, symbol table, syntax analysis, semantic analysis, code generation

Question 30

lexical analysis

Answer 30

white space and comments are removed. keywords, constants, identifiers and operators are replaced with tokens

Question 31

symbol table

Answer 31

the lexer will create a symbol table for every keyword and identifier in the program which helps keep track of the runtime memory address of each identifier

Question 32

syntax analysis

Answer 32

tokenized code is compared to syntax rules of the language, if a section violates any rules an error is generated with details of what and where it is, a full error report is given back to the user of all errors found

Question 33

semantic analysis

Answer 33

checks for errors where valid syntax doesnt produce a valid program

Question 34

code generation

Answer 34

machine code is generated

Question 35

code optimsiation

Answer 35

aims to improve efficiency by removing redundant instructions, replacing inefficient code

Question 36

libraries

Answer 36

pre-written, compiled, tested and checked pieces of code that gives developers shortcuts to achieve what they need without repeating code

Question 37

linkers

Answer 37

software responsible for linking libraries to code that uses them, put the appropriate memory addresses in place so that the program can call and return from a library function

Question 38

loaders

Answer 38

copy the program and any linked subroutines into main memory to run

Question 39

bytecode

Answer 39

an intermediate step between high level languages and machine code

Question 40

bytecode how

Answer 40

the high level language may be compiled or interpreted into byte code which is then executed by a bytecode interpreter

Question 41

bytecode advantages

Answer 41

platform independence, acts as an extra security layer