1.2.2 Applications Generation

Question 1

Applications software

Answer 1

Designed to be used by the end user to complete one specific task

Question 2

4 types of application software

Answer 2

Off the shelf, bespoke, proprietary and open source

Question 3

Database management software

Answer 3

Used to manage data in a database without having to access the database manually

Question 4

Off the shelf software

Answer 4

Ready made software available for anyone to purchase

Question 5

Bespoke software

Answer 5

Software that is custom created for a specific user

Question 6

Open source software

Answer 6

Allows anyone to access the source code
Open source licenced but free to use
Anyone can sell a modified version but the owner has to accept changes to the source code

Question 7

Open source advantages and disadvantages

Answer 7

+ free licence, people collaborate to improve it, new versions need the same licences
- can’t make money, support must be paid for

Question 8

Closed source/ proprietary software

Answer 8

Does not allow access to the store code, users must pay the company for the licence to use the software. There are restrictions on how it can be used

Question 9

Proprietary advantages and disadvantages

Answer 9

+ Support is usually free, can be free, free updates

- Source code not easily available, cannot be altered/shared

Question 10

Freeware

Answer 10

Software is free to use but source code is unavailable

Question 11

Systems software

Answer 11

Low-level software responsible for running the computer system smoothly, providing a platform for applications software

Question 12

Examples of systems software

Answer 12

Operating systems, utility programs, library programs, translators

Question 13

Disk defragmenter

Answer 13

Rearranges your data so that it is stored contiguously

Question 14

Automatic backup

Answer 14

Stores your data in servers elsewhere in case of an issue. Automatic so you don’t forget to do it

Question 15

Automatic updating

Answer 15

Upgrades the system software to upgrade performance and removes bugs without us remembering to do it

Question 16

Virus checking

Answer 16

Uses firewalls to stop viruses getting onto devices and anti-malware to fix them, minimises risk of viruses affecting you

Question 17

Compression software

Answer 17

Stores the data in a smaller area, allowing you to store more data and instructions.

Question 18

File manager

Answer 18

Allows the users to move/view/rename/open their files

Question 19

Low Level Language

Answer 19

e.g. machine code (made up of operand and opcode) - first generation language
assembly code (opcode replaced with mnemonic ) - second generation language
Used in embedded systems/mobile phones

Question 20

Low Level Language advantages and disadvantages

Answer 20

+ fast, uses little space, manipulates individual data

- hardware specific

Question 21

High Level Language

Answer 21

Appear similar to English

One instruction is the equivalent to many in assembly code

Question 22

What are compilers, assemblers and interpreters?

Answer 22

A type of translator (convert to machine code so it can be executed)

Question 23

Assemblers

Answer 23

Translate from assembly language to machine code

Each line of assembly code is a line of machine code

Question 24

Assemblers advantages and disadvantages

Answer 24

+ checks for errors for you

- particular to the computer hardware

Question 25

Source program

Answer 25

The program written by the user in assembly code

Question 26

Object code

Answer 26

The machine code created by the translator

Question 27

Compiler

Answer 27

Converts source code to machine code in a .exe file

Question 28

Compiler advantages and disadvantages

Answer 28

+ the exe file can be saved separately and run whenever, checks for errors multiple times, object code executes faster - takes longer to compile initially, different needed for different hardware platforms, all must be recompiled if changes need to be made

Question 29

Interpreters

Answer 29

Compile into machine code one line at a time | Checks each line for errors individually before compiling

Question 30

Interpreters advantages and disadvantages

Answer 30

+ locates errors, doesn't look at the whole program for each line, more portable across platforms - doesn't produce object code so needs interpreting for every run

Question 31

Byte Code

Answer 31

Intermediate between compiling and interpreting Used by most interpreted languages, doesn’t interpret one line at a time Done so that it can be interpreted to different computer architecture

Question 32

3 stages of compilation

Answer 32

Lexical analysis Syntax analysis Code generation

Question 33

Lexical Analysis

Answer 33

Takes the source program, removes comments and whitespace and replaces symbols with tokens of the type e.g. operator, variable Variable names are stored for later use Stored in a symbol table

Question 34

Syntax Analysis

Answer 34

Tokens checked to see if the order makes sense Syntax errors are flagged and an abstract syntax tree is produced Expresses in binary to check

Question 35

Code Generation

Answer 35

Code is actually converted into machine code from the abstract syntax tree Each high-level function creates many low-level Code can be optimised e.g. smallest size/ optimised performance

Question 36

Semantics

Answer 36

About the meanings

Question 37

Syntax

Answer 37

About the structure

Question 38

Parsing

Answer 38

Made up of syntax and syntactic analysis | Analyses a string of symbols to check it conforms to rules

Question 39

Semantic Parsing

Answer 39

The meaning and implications are determined and necessary actions taken Semantic analysis is done after to gain the meaning

Question 40

Libraries

Answer 40

Sets of compiled and compiled functions in a language, can be called within a program + save time, cover complex areas, can be used in many languages

Question 41

Linker

Answer 41

Needs to put the appropriate memory addresses in place so that the program can return and call from a library function

Question 42

Loader

Answer 42

Copies the program and any linked subroutines into main memory to run The code can assume the program in memory address 0 The loader needs to relocate the memory addresses so that it knows where to go to call functions

Question 43

Full backup

Answer 43

Every file is copied to an alternative storage device

Question 44

Incremental backup

Answer 44

Only the files that have changes since the last backup are copied

Question 45

Utility software

Answer 45

Has a specific function linked to the maintenance of the OS

Question 46

Static

Answer 46

Modules and libraries are added directly into the main file, increasing their size

Question 47

Dynamic

Answer 47

Addresses of modules and libraries are included in the file. Files remain small and external updates feed through to the main file

Question 48

Examples of utility software

Answer 48

Encryption, compression, backup