Computer systems Flashcards
Operating system
software that controls the computer’s hardware and software resources - acts as a bridge between user and computer hardware
Application Programming Interface (API)
layer of software that allows application programs to call on the services of the operating system
Memory management
optimizes the use of the computer or device’s internal memory so that memory is allocated efficiently between processes that are running
Processor scheduling
determines the order in which processes will be executed, which allows for multi-tasking
Scheduler
OS module responsible for making sure that processor time is used as efficiently as possible
Virtual memory
process of optimizing RAM storage by borrowing hard drive space
Backing store management
tracks where files and programs are stored and which parts are available for storage - allows user to move, delete and protect files and folders from unauthorised access
Peripheral management
ensures efficient communication with I/O devices and manages functionality issues
Interrupt handling
process of handling interrupt signal from a peripheral or software program that disrupts OS processing of its current list
Multi-tasking
appearance of running more than one application in memory simultaneously
Machine code
uses only zeros and ones to represent instructions
Accumulator
register inside the processor in which arithmetic calculations are carried out
Opcode
part of the instruction that specifies which operation the processor should perform
Operand
contains value/set of values relevant to opcode - can be actual data or reference to memory location of data
Assembly language
allows programmers to write human-readable code that represent binary equivalent in machine code
High-level language
programming language designed to be easy for humans to read and write
Low-level language
programming language designed to be easy for a computer to execute - also called machine language or assembly language
Compiler
A program that translates instructions or code into an executable form for the computer - does NOT execute code
Interpreter
converts a program written in a higher level language into a lower level language and executes it line-by-line
Assembler
that translates an assembly-language program into executable machine code
Bytecode
source code that has been compiled into low-level code designed to run on a virtual machine
Hardware
describes electrical or electro-mechanical part of a computer and its input, output and storage devices
Software
programs and other operating information used by a computer
System software
software needed to run the computer’s hardware and application programs
Disk defragmenter
tool that reorganises the files and unused space on a computer’s hard disk so that the operating system accesses data more quickly and programs run faster
Virus checker
utility program that seeks out and eliminates viruses
Libraries
ready-compiled programs which can be run when needed and are grouped together in software libraries
Application software
consists of programs that perform specific user-oriented tasks
General purpose software
software that can be used for many different tasks
Special purpose software
software designed to support one specific task or set of tasks
“off-the-shelf”
standardised software applications that are mass-produced, available to the general public, and can be used immediately after purchase
Bespoke software
software that is custom-made for a specific task or for a specific company
