Section 4 - Hardware and software Flashcards
What is hardware?
physical components of the computer system
What is software
code/programs that are executed
what are the two classifications of software
system and application
what is system software
The software needed to manage the computers systems
what are the parts of system software
- operating system
- utility programs
- libraries
- programming language translators
what is a utility program
system software designed to optimise the performance of the computer or perform tasks
what are library programs
ready complied programs that can be run when needed, included pre written code
what are some examples of utility programs
virus scanners, disk defragmenters, system monitors, file managers
what are translators
convert source code into machine code
what are the types of application software
general purpose and special purpose
what is general purpose software
software that can be used for many different purposes.
such as a word processor, spreadsheet or graphics package
what is special purpose software
performs single specific tasks
what is application software
programs that perform specific user-orientated tasks`
what is an operating system
set of programs that manages the operations of the computer for the user
what are the functions of an operating system
- hides complexities of hardware from user
- allocates memory to processes
- allocates processors to processes
- handles interrupts
- allocates I/O devices to processes
- allocates space on storage devices for processes
what does OS memory management mean
each program open must be allocated a specific area of memory whilst the computer is running
what does OS processor sceduling mean
allocating processor time to each application
what does OS backing store management
managing files and applications that have been transferred to backing storage, and manage free areas of storage.
what is machine code
a low-level programming language in binary where every instruction contains an operation (opcode) and an operand (data or address of data)
what is assembly language
a low-level programming language where each opcode is a mnemonic
differences between machine code and assembly language
- machine code written in binary, assembly code written in mnemonics
- assembly language needs translating before it can run, machine code doesn’t
what is a low-level programming language
a language where the code reflects how the computer actually carries out the instruction
what is a high-level programming language
each instruction is a command to perform a step in the program
each instruction will be translated to several low-level language instructions.
advantages of high-level compared to low-level
- high-level languages are easier for humans to interpret
- high-level languages have extra features like abstract data types and built in functions
- high-level have a wider range of programming structures
- high-level languages are easier to understand/debug/maintain
- high-level languages are quicker to write
advantages of low-level languages compared to high-level languages
- not all low-level languages need to be translated, unlike high-level
- low-level languages use less memory when executing
- low-level languages execute faster
- low-level languages can directly control hardware
what is an assembler
translates an assembly language program into machine code
input is called source code, output is called object code
what is a compiler
a program that translates high-level languages (source code) into machine code (object code)
it scans through the code several times and then saves the object code produced
what is an interpretter
a program that translates high-level languages
it looks at each line of the source code and if it has no errors, executes the command
if it finds an error it does not attempt to run any of the program till its fixed
what is bytecode
most high-level languages use combined compiling and interpreting that results in bytecode, executed by a bytecode interpreter
what are the advantages of bytecode
- platform independence means many computers can run it
- it provides an extra security layer between the computer and the program, meaning you only have to run the bytecode interpreter rather than the bytecode itself
what are the advantages of compilers over interpreters
- compilers produce object code that can be saved onto a disk an run whenever required
- object code executed faster than interpreted code
- object code from a compiler can be executed without having a compiler
- compiler object code is more secure
what are the advantages of interpreters over compilers
- if an error is found in compilers object code the whole thing has to be recompiled
- interpreters mean there’s no lengthy recompilation every time an error is discovered
- interpreters are easier to partially test and debug programs
