Output Devices
Once data are processed, output devices translate the language of bits into a form
humans can understand. Output devices are divided into two basic categories: those
that produce hard copy, including printers and plotters; and those that produce
soft (digital) copy, including monitors (the most commonly used output device).
Soft copy is also produced by speakers that produce speech, sound, or music.
Secondary Storage Devices
The memory we have discussed so far is temporary or volatile. To save your work
permanently, you need secondary storage devices. Magnetic disk and magnetic tape
and optical disks are used as secondary storage media. Magnetic media (disk,
diskette, tape, and high-capacity Zip disks) store data and programs as magnetic spots or electromagnetic charges. High-capacity optical disks (compact disks [CDs]
or digital video disks [DVDs]) store data as pits and lands burned into a plastic disk.
Solid-state memory devices include flash memory cards used in notebooks, memory
sticks, and very compact key chain devices; these devices have no moving parts,
are very small, and have a high capacity. USB flash drives have a huge capacity for
information.
SOFTWARE
Software refers to the programs—the step-by-step instructions that tell the hardware
what to do. Without software, hardware is useless. Software falls into two general categories:
system software and application software.
System Software
System software consists of programs that let the computer manage its resources.
The most important piece of system software is the operating system. The operating
system is a group of programs that manage and organize resources of the computer.
It controls the hardware, manages basic input and output operations, keeps track
of your files saved on disk and in memory, and directs communication between
the CPU and other pieces of hardware. It coordinates how other programs work
with the hardware and with each other. Operating systems also provide the user
interface—that is, the way the user communicates with the computer. For example,
Windows provides a graphical user interface, pictures or icons that you click on with
a mouse. When the computer is turned on, the operating system is booted or loaded
into the computer’s RAM. No other program can work until the operating system is
booted.
Application Software
Application software allows you to apply computer technology to a task you need
done. There are application packages for many needs.
Word-processing software allows you to enter text for a paper, report, letter, or
memo. Once the text is entered, you can format it, that is, make it look the way you
want it to look. You can change the size, style, and face of the type. In addition, margins
and justification can be set to any specifications. Style checkers can help you
with spelling and grammar. Word-processing software also includes thesauri, headers
and footers, index generators, and outlining features.
Electronic spreadsheets allow you to process numerical data. Organized into
rows and columns intersecting to form cells, spreadsheets make doing arithmetic
almost fun. You enter the values you want processed and the formula that tells the
software how to process them and the answer appears. If you made a mistake entering
a value, just change it and the answer is automatically recalculated. Spreadsheet
software also allows you to create graphs easily—just by indicating what cells you
want graphed. Electronic health records (EHRs) can use spreadsheets to graph a
series of a patient’s blood values over time.
Database management software permits you to manage large quantities of data
in an organized fashion. Information in a database is organized in tables. The database
management software makes it easy to enter data, edit data, sort or organize
data, search for data that meets a particular criterion, and retrieve data. Once the
structure of the table is defined and the data entered, that data can be used for a
variety of purposes without being retyped. Eye-pleasing, businesslike reports can
easily be generated by simply defining their structure.
There are also specialized software packages used in specific fields such as medicine.
For example, there are specialized accounting programs used in medical
offices. Microsoft is considering developing a new software package for the health
care industry. Communications software includes Web browsers, such as Internet Explorer.
These programs allow you to connect your computer to other computers in a
network.
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