1. Hardware vs. Software
Computer systems consist of both hardware and software.
Hardware refers to anything you can physically touch.
Keyboards, mice, monitors, and motherboards are all hardware.
Software consists of the instructions issued to the computer to perform specific tasks.
The software on a computer system refers to the programs that make the computer run.

2. Types of Software
Although there are literally thousands of software programs you can buy, there are really only two types of software: application and systems.
Application software computer software created to allow the user to perform specific a job or task.
Systems software is computer software responsible for the general operation of a computer system, including the operation of hardware, running application software, and file management.

3. Application Software
Application software is also called productivity software.
It allows an end user to perform some task.
The most commonly used categories of application software are
Word-processing programs
Spreadsheet software
Database software
Presentation software
Desktop publishing programs
Games
Graphics Software

4. Application Software
Most application software is defined by the file type.
File type – an extension at the end of a file name, indicating which application was used to create a document
File Extensions for Microsoft Office
.docx is Microsoft Word
.xlsx is Microsoft Excel
.pptx is Microsoft PowerPoint

5. Systems Software
Systems software consists of programs that coordinate and control the resources and operations of the computer itself.
The three categories of systems software are
Operating systems
Utility programs
Language translators

6. Systems Software – Operating Systems
Operating systems system software that acts as a "go-between", allowing computer hardware and other software to communicate with each other.
There are many brands and versions of operating systems.
An operating system is designed to work with a specific processor chip.
For example, Windows operating systems are designed to work with an Intel processor (or clone) and will not usually work on a Macintosh computer.

7. Illustration of an Operating System
This figure shows how an operating system acts as an interface between the user, the application programs, and the computer.

8. Systems Software - Utilities
Utility programs are designed to help perform housekeeping chores for the computer.
They can be designed to
Manage the computer’s resources.
Do file management.
Format disks.
Copy files from one disk to another.
Back up data to disk or tape.

9. Common Utility Programs
Disk Formatting prepares disk to have files stored on it.
File Management is a program on a computer that allows the user to create, edit, view, print, rename, copy, or delete files, folders, or an entire file system
File Recovery attempts to recover a file that has been erased.

10. Common Utility Programs
Uninstall removes an application program no longer needed.
Diagnostic provides detailed information about the computer system and attempts to locate problems.
File Conversion converts a file from one format to another.

11. Common Utility Programs
Disk Compression frees up storage space on a disk by compressing existing files.
Backup makes a duplicate copy of the contents of a secondary storage device.
Antivirus protects the computer system from viruses.
Disk Defragmentation attempts to place segments of each file on the hard disk as close to one another as possible.

12. Systems Software – Language Translators
Computers cannot read program statements in programming language format, such as Visual Basic or Java program statements.
Language translator programs convert English-like software programs into machine code that can be understood by the computer.
Each converted English-like instruction may be translated into many machine code instructions.
Once converted to machine code, the program can be run and executed by the computer.

13. Microcomputer Operating System Interfaces
The user interface of an operating system is what we are all familiar with.
The User Interface is the part of the operating system that you interact with when using your computer.

14. Microcomputer Operating System Interfaces
There are two commonly used types of operating system interfaces:
Command-line interface: With this interface, you must type exact commands into the computer from a command prompt.
This is not a user-friendly interface, and you must memorize many commands and keywords.
Graphical user interface: Users manipulate on-screen icons to perform functions, usually with a mouse or other pointing device.

15. User Interface Comparison
The figure on the left shows a command-line interface, where commands are typed in at the prompt. The figure on the right is a graphical user interface (GUI) where users perform actions by clicking and manipulating icons.

16. Microcomputer Operating Systems
If your computer is a Macintosh, you are probably using a Mac OS.
Macintosh computers used one of the first GUI operating systems ever developed.
If your computer is a PC or is PC-compatible, you are most likely using one of these operating systems:
DOS
A combination of DOS and Windows
A stand-alone version of Windows

17. The Mac OS Macintosh computers were developed by Apple Computer.
Macintosh had one of the first GUI operating systems where icons were used to represent programs and files.
To activate an icon, the user clicked it with the mouse.
This was also the first operating system to provide an on-screen help system.

18. The DOS Operating System
IBM introduced its first PC in Its operating system was called DOS, which stands for Disk Operating System.
IBM called it PC-DOS. The operating system was licensed from its creator, Microsoft, who sold it under the name MS-DOS.
DOS was a command-line interface operating system where the user had to enter commands at a screen prompt.
It was a single-tasking operating system, which meant that only one program at a time could be executed.

19. The Windows Operating System
Windows was Microsoft’s first GUI operating system, released in 1987.
The first versions were called operating environments because they acted as a shell around the DOS operating system and worked in combination with DOS.
Applications installed on a Windows system appeared as icons.
As with the Mac OS, the user activated a Windows program by clicking the icon.

20. Windows Versions
The earliest versions of Windows were labeled Windows 3.0, 3.1, etc.
The first true multitasking version of Windows was Windows 95.
This version also included support for networking computers.
Multitasking is the ability to run more than one program at a time.

21. Windows Versions
Windows 98 improved on Windows 95 and offered Internet integration and support for the USB bus.
Windows 2000 was an update to Windows 98 and Windows NT and included tools for Web site creation.
We use Windows XP, which provides increased stability and device recognition over earlier Windows versions.
Windows 7 is the latest version of Windows Operating System.

22. Macintosh vs. Windows User Interface
The image on the left is an example of a Macintosh interface window. On the right is the Windows 2000 interface.

23. The Unix Operating System
Unix is another early operating system that is still widely used today.
It was developed by AT&T as part of their phone-switching system.
It was developed to be a portable operating system.
That means that it was meant to run on any hardware platform.
It is a command-line interface system, although there are now several GUI interface products available for Unix and Linux.

24. Example of a Unix System
Linux and IBM’s AIX offer a graphical user interface shell for a Unix operating system, as shown here. This provides greater ease of use while taking full advantage of Unix’s speed and reliability.

25. Network Operating Systems
A network operating system (NOS) is designed to allow multiple computers to be connected and talk to each other.
Networks are computers that are connected to each other.

26. Network Operating Systems
While there are many network operating systems available, the most popular are
Microsoft Windows NT and Windows 2000
Novell’s Netware
IBM’s Warp Server
Most network operating systems makes uses logon to use them.
Logon is the action of gaining access to a computer or a network by entering a username and password; also called Login/Sign In