Operating System types of operating system functions of operating memory management file and folder management desktop and its composition mouse and keyboard operations tools and softwares

2. An operating system (OS) is the program that, after being
initially loaded into the computerby a boot program, managesall the other programs
in a computer.
The other programs are called applications or application programs. The application
programs makeuseof the operating system by makingrequests for services through
a defined application program interface (API). In addition, users can interact directly
with the operating system through a user interface such as a command line or a
graphical user interface (GUI).
Distinguished by the response time and how data is entered into the system.
 Single-user
 Multi-user
 Multi Tasking
 Multi Processing
 Embedded
 Real-time operating system
SINGLE-USER :
As opposed to a multi-user operating system, are usable by a single user at
a time. Being able to have multiple accounts on a Windows operating system does
not make it a multi-user system. Rather, only the network administrator is the real
user. But for a Unix-like operating system, it is possible for two users to login at a
time and this capability of the OS makes it a multi-user operating system.
OPERATING SYSTEM
TYPES OF OPERATING SYSTEM

3. MULTI-USER:
A multi-user operating system allows multiple users to access a computer
system concurrently. Time-sharing system can be classified as multi-user systems
as they enable a multiple user access to a computer through the sharing of time.
MULTI TASKING
In this case operating system allows the execution of multiple tasks at one
time, it is classified as a multi-tasking operating system. Multi-tasking can be of two
types namely, pre-emptive or co-operative. In pre-emptive multitasking, the
operating system slices the CPU time and dedicates one slot to each of the
programs. Unix-like operating systems such as Solaris and Linux support pre-
emptive multitasking. Cooperative multitasking is achieved by relying on each
process to give time to the other processes in a defined manner. MS Windows prior
to Windows 95 used to support cooperative multitasking
MULTI PROCESSING
A multiprocessing operating system allows a program to run on
more than one central processingunit (CPU)at a time. This can come in
very handyin some work environments,at schools,and even for some
home-computing situations.
EMBEDDED
Embedded operating systems are designed to be used in embedded
computer systems. They are designed to operate on small machines like PDAs
withless autonomy. They are able to operate with a limited number of resources.
They are very compact and extremely efficient by design. Windows, CE and
Minix 3 are some examples of embedded operating systems.

4. REAL-TIME
A real-time operating system is a multitasking operating system that aimsat
executing real-time applications. Real-time operating systemsoftenuse specialized
scheduling algorithms so that they can achieve a deterministic nature of behavior.
The main object of real-time operating systems is their quick and predictable
response to events. They either have an event-driven or a time-sharing design. An
event-driven system
The Following are the functions of Operating system
1. Hardware management
Operating systems control all attached devices, controlling their operations and
interactions. Examples of such hardware’s include a hard disk, optical drives, video
cards and external port controllers, such as universal serial bus abbreviated USB
among others.
2. Provide environment for application software to function
Application software is a program or group of programs designed for end users.
An operating system provides an environment for software applications to function
as designed and intended. An application software is a specific software which is
used to perform a specific task.
Application software’sare designed torun witha particular operating system inorder
to function, operating system needs to display any interfaces and facilitate
communications among the programs and your computer's connected hardware
3. Provide structure for data management An operating system displays
structure/directories for data management. We can view file and folder listings and
manipulate on those files and folders like (move, copy, rename, delete, and many
others).
FUNCTIONS OF OPERATING SYSTEM

5. The operating system is also in charge of accessing, storing and retrieving data on
the computer's hard drive. Stored data is managed temporarily in the computers
read-only memory RAM. Some data stored and retrieved include document files,
picture data, videos, and music.
4. Monitor system health and functionality
Operating system monitors the health of our system’s hardware, giving us an idea
of how well (or not) it’s performing. We can see how busy our CPU is, or how quickly
our hard drives retrieve data, or how much data our network card is sending,
monitors system activity for malware among others.
The operating system manages computer's resources, by allocating them as
needed. Which tasks the central processing unit (CPU) and in what order, which
functions or applications are assigned processing power among others.
5. Network Communication
The operating system function to facilitate network communication through the
enabling of the connected network devices to communicate with the computer and
with any programs that require them. Examples, Network cards, such as Ethernet
ports and wireless local area network (LAN) cards, enable connection to networks
but they also require an operating system to interface them.
6. Loading and Execution
Operating systemsprovidefacility toloads program in the memory andthenexecute
them appropriately.
7. Data security
Data security define the protection of computer system resources such as central
processing unit(CPU), memory, disk, software programs and most importantly
data/information stored in the computer system
Operating system protects the data stored on the computer from illegal use,
modification or deletion through different mechanisms. Such mechanisms include
authentication, system threats among others.

6. 8. Process management
Central processing unit (CPU) can perform one task at one time. If there are many
tasks, operating system decides which task should get the central processing unit
(CPU) for execution.
9. Providing interface
User interface controls how you input data and instruction and how information is
displayed on a monitor. The following are the operating systems interfaces
Graphical-line interface: This is an interface that works at the point of contact
between a computer and its user, and which employs graphic
Memory management is the process of controlling and
coordinating computer memory, assigning portions called blocks to various
running programs to optimize overall system performance. Memory
management resides in hardware, in the OS (operating system), and in
programs and applications.
In hardware, memory management involves components that
physically store data, such as RAM (random access memory) chips, memory
caches, and flash-based SSDs (solid-state drives). In the OS, memory
management involves the allocation (and constant reallocation) of specific
memory blocks to individual programs as user demands change. At the
application level, memory management ensures the availability of adequate
memory for the objects and data structures of each running program at all
times. Application memory management combines two related tasks, known
as allocation and recycling.
MEMORY MANAGEMENT

7. A desktop is a computer display area that represents the kinds of objects one
might find on top of a physical desk, including documents, phone books, telephones,
reference sources, writing and drawing tools, and project folder.
The main components of the desktop are the icons on the desktop and the panel at
the bottom of the screen.
Desktop icons represent files, directories, applications, functions, and removable
media, like CDs or DVDs.
The desktop has the following icons by default:
 Trash
Contains files and folders that have been deleted. For information about using the
trash.
 My Computer
Displays information about hardware, network status, operating system, hard
disks, commonfolders, and removable devices.
 Network Browsing
Displays network services you can access. Someof the services might require
authentication
DESKTOP AND ITS COMPOSITION

8. The panel typically consists of the following areas:
 Main Menu Icon
By default, the left end of the panel has an icon that opens the main menu (in KDE
also called K menu), similar to the start button on the MS Windows desktop. The
main menu has a well-ordered structure for accessing the main applications. It also
contains menuitems for major functions like logging out or searching for
applications. For more information, see Abschnitt 1.3.1, „Accessing the Main
Menu“.
 Quick Launcher
Next to the main menu icon, find the quick launcher. It holds someicons for the
most important functions or applications to enable you to start them without going
through the main menu.
 Desktop Previewer
Next to the quick launcher, find the desktop previewer, which shows your different
desktops. These virtual desktops enable you toorganize your work. If you use many
programs simultaneously, youmight want to run some programs in one desktop and
other programs in the other desktop. To switch between desktops, click the
desktop symbol in the panel.
 Taskbar
The taskbar is located next to the desktop previewer. By default, all started
applications and open windows are displayed in the taskbar, which allows you to
access any application regardless of the currently active desktop. If you click a
window title in the taskbar, the application is movedto the foreground. If it is already
in the foreground, clicking minimizes the application.

9.  System Tray
The rightmost part of the panel usually holds the system clock, the volume control,
and several other helper applications.
MOUSE OPERATIONS
There are four basic mouse operations that you can perform:
<Click>
To select an item or choose a menucommand, point the mouse at it with the
pointer and <Click> the left mouse button.
<Click and Drag>
To movean item is called dragging. To complete this operation, point at the item,
<Click> it and hold downthe left mouse button. While holding down the left mouse
button drag the item where you want it to be. Release the button. Note: Practice
this a bit before doing it, since you can inadvertently drag an item anywhere.
<Double-Click>
This is a shortcut methodused to access an item or to open or close a
window quickly without using a menu. To complete this operation, point the
mouse pointer to the item and <Double-Click> it with the left mouse button.
KEYBOARD AND MOUSE BASIC
OPERATIONS

10. <Right-Click>
When you click the right mouse button you can access a drop downmenu to
choose what you can do withthe item, such as "copy,"paste", etc. Every menu is
specific to what you click. To perform this operation, point at the desired item or
object and <Click> the right mouse button ONLY once.
KEYBOARD OPERATIONS
A keyboard's primary function is to act as an input device. Using a keyboard,
a person can type a document, use keystroke shortcuts, access menus, play
games and perform a variety of other tasks. Keyboards can have different keys
depending on the manufacturer, the operating system they'redesigned for, and
whether they are attached to a desktop computer or part of a laptop. But for the
most part, these keys, also called keycaps, are the same size and shape from
keyboard to keyboard. They're also placed at a similar distance from one another
in a similar pattern, no matterwhat language or alphabet the keys represent.
Most keyboards have between80 and 110 keys, including:
 Typing keys
 A numeric keypad
 Function keys
 Control keys

11. FILE MANAGEMENT:
A file management system is a type of software that manages data files in a
computer system. It has limited capabilities and is designed to manage individual or
group files, such as special office documents and records. It may display report
details, like owner, creation date, state of completion and similar features useful in
an office environment.
A file management system is also known as a file manager.
FOLDER MANAGEMENT
Folder management is organizing and keeping track of and folders, helping
you stay organized, so information is easily located. ... Windows allows you to
organize folders and files in a file hierarchy, imitating the way you store paper
documents in real folders.
FILES AND FOLDER MANAGEMENT

12. TOOLS
 Straight head screw driver
 Phillipes head screw driver
 Tweezers
 Needle nosed pliers
 Wire cutter
 Chip extractor
 Hex wrench set
 Tox screw driver
SOFTWARES
A computer software is collection of data or computer instruction
that tell the computer how to work
There are twotypes of software
a. System software
b. Application software
SOFTWARE EXAMPLES
Internet browser Google chrome fire fox
and internet
Movieplayer VLC , window media
player
Operating system Android , Linux macos
Graphic software Adobe Photoshop,
TOOLS AND SOFTWARES