At the simplest level, an operating system
does two things:
1.
It manages the
hardware and software resources of the system. In a desktop computer, these resources include such things as the processor, memory, disk space and more (On a cell phone, they include the keypad, the screen, the address book, the
phone dialer, the battery and the network connection).
2.
It provides a stable,
consistent way for applications to deal with the hardware without having to
know all the details of the hardware.
The first task,
managing the hardware and software resources, is very important, as various
programs and input methods compete for the attention of the central
processing unit (CPU) and demand memory, storage and input/output
(I/O) bandwidth for their own purposes. In this capacity, the operating system
plays the role of the good parent, making sure that each application gets the
necessary resources while playing nicely with all the other applications, as
well as husbanding the limited capacity of the system to the greatest good of
all the users and applications.
The second task,
providing a consistent application interface, is especially important if there
is to be more than one of a particular type of computer using the operating
system, or if the hardware making up the computer is ever open to change. A
consistent application program interface (API) allows a software
developer to write an application on one computer and have a high level of
confidence that it will run on another computer of the same type, even if the
amount of memory or the quantity of storage is different on the two machines.
Even if a particular
computer is unique, an operating system can ensure that applications continue
to run when hardware upgrades and updates occur. This is because the operating
system -- not the application -- is charged with managing the hardware and the
distribution of its resources. One of the challenges facing developers is
keeping their operating systems flexible enough to run hardware from the
thousands of vendors manufacturing computer equipment. Today's systems can
accommodate thousands of different printers, disk drives and special
peripherals in any possible combination.
Comments
Post a Comment