Many people think of a PC as
comprising solely physical hardware, but hardware is just a useless pile of
silicon, metal, and plastic unless you have software to make it do something.
Software is a set of detailed instructions that allow a computer to perform a
task or group of tasks. Software is usually categorized as being one of three
types:
Applications programs : Applications programs are what most people think of when
they hear the word software. These programs are designed to perform specific
user-oriented tasks, such as creating a word processing document or
spreadsheet, browsing the Web, reading and replying to email, managing your
schedule, creating a presentation, or recovering a deleted file. Hundreds of
thousands of applications programs are available, from comprehensive office
suites such as Microsoft Office, to vertical market packages such as medical
office billing software, to single-purpose utilities such as WinZip.
Operating system : An operating system is software that manages the PC
itself, providing such basic functions as the ability to write and read data
from a disk or to display images on the monitor. A PC can run any of dozens of
operating systems, including DOS, Windows 95/98/98SE/Me, Windows NT, Windows
2000, Windows XP, Windows 7, Linux and other Unix variants, NetWare, BeOS, and
many others.
Device drivers : We said that the operating system determines which
peripherals you can use. That's true, but only indirectly. Operating systems
themselves natively recognize only the most basic, standardized system
components things like memory, the system clock, and so on. Device drivers are
small programs that work at a very low level to integrate support for other
devices into the operating system. Using device drivers allows an operating
system to be extensible, which means that support for new devices can be added
incrementally, without updating the operating system itself.
No comments:
Post a Comment