Chapter 5 -IT Flashcards
System Software: OS and utility programs
System software
Refers to the OS and utility programs that control a computer system and allow you to use that system
What does the system software do?
Enables the boot process, launches applications, transfers files, controls hardware configuration, manages files on the hard drive, and protects from unauthorized use
Application software
Refer to the programs that allow a user to perform specific tasks on a computer
word processing, playing games ,browsing the web, listening to music
Operating system
Is a collection of programs that manage and coordinate the activities taking place within a computer
Acts as an intermediary between the user and the computer and between the app programs and system hardware
Parts of OS
Kernel-communicates directly with the hardware
Shell-works with the application and user
Function of an OS: Interfacing with users and Booting the PC
Interfacing with users(typically via a GUI)
Booting the computer
Loads the essential part of OS(kernel) into memory
Determines the hardware connected to computer
Reads startup instructions
Startup programs are launched automatically
Windows users can control via the Task manager
Other instructions are stored in the windows registry
Windows task manager
Shows all running programs and processes and allows you to specify startup programs
Configuring devices so they operate properly
Device drivers communicate with peripheral devices
Most OS look for and recognize new devices each time the computer boots
Device drivers can be updated and reinstalled as needed
File management
Keeps track of stored files on computer so they can be retrieved when needed
Multitasking
Refers to the ability of an OS to have more than one program(task) open at one time
CPU rotates between tasks
Switching is done quickly
Appears as though all programs are executing at the same time
Multithreading
Enables the computer to rotate between multiple threads so that processing is completed faster and more efficiently
A thread is a sequence of instructions within a program that is independent of other threads
Tasks are performed sequentially
Multiprocessing
Using two or more CPUs or CPU cores in one computer to perform work more efficiently. Each CPU or core typically works on a different job
Used with computers and devices that have multi-core CPUs and/or multiple CPUs
Parallel processing
Using two or more CPUs or CPU cores in one computer to perform work more efficiently. The CPUs or cores typically work together to complete one job quickly. Used most often with supercomputers
In either case, tasks are performed simultaneously
Sequential vs Simultaneous processing
Sequential-tasks are performed one right after the other
Simultaneous-Multiple tasks are performed at the exact same time
Virtual memory
A memory-management technique that uses hard drive space as additional RAM
A buffer
Is an area in RAM or on the hard drive designated to hold data that is waiting to be used by the computer
Buffering or spooling places items in a buffer so they can be retrieved by the appropriate device when needed
Graphical user interface
Has icons, buttons, and other objects that the user selects to issue commands
A command line interface
Requires the user to input text-based commands using the keyboard
Categories of OS
Personal(desktop)
Server(network)
Mobile OS
Embedded OS
Personal(desktop)
OS systems are designed to be installed on a single computer
Server(network)
OS are designed to be installed on a network server
Client computers still use a personal OS
Server as controls access to network resources
Mobile OS
Are used with smartphones and other mobile devices
Embedded OS
Are built into devices (cars, kiosks)
Operating Systems for Personal computers and servers
DOS(Disk operating system)
DOS traditionally used a command-line interface
Dominant OS in the 1980s and early 1990s
Created originally for IBM microcomputers
Created for use with IBM-compatible computers
Can enter DOS commands in windows using the command prompt window
