Computer Memory


In computing, memory refers to the physical devices used to store programs (sequences of
instructions) or data (e.g. program state information) on a temporary or permanent basis for use in a
computer or other digital electronic device. The term primary memory is used for the information in
physical systems which function at high-speed (i.e. RAM), as a distinction from secondary memory,
which are physical devices for program and data storage which are slow to access but offer higher
memory capacity.
There are two types of memory
Read only memory
Read only memory (ROM) is the permanent memory which is used to store important control
programs and systems software to perform a variety of functions, such as booting up or starting up
programs. ROM is non-volatile. That means the contents are not lost when the power is switched off.
Its contents are written at the time of manufacture, but in modern (2012) computers may be changed
using special software.
Random access memory
Random access memory (RAM) is used as the working memory of a computer system. It stores input
data, intermediate results, programs, and other information temporarily. It can be read and written. It
is usually volatile, that is all data will be lost when the power is turned off. In most cases it is loaded
again from hard disk.
 

Concept of hardware and software
Hardware and Software: The Basics
Hardware – physical aspects of computers, telecommunications, and other information technology
    devices
Example: Keyboard, monitor
Software -a general term for the various kinds of programs used to operate computers and related
    devices
Example: Microsoft Excel
Six Categories of Hardware
ʕ⤠Input Device
ʕ⤠Output device
ʕ⤠Storage device
ʕ⤠Central processing unit (CPU)
ʕ⤠Telecommunications device
ʕ⤠Connecting device
 
Two main types of software
Application software - software used to solve specific problems or perform specific tasks
System software - handles tasks specific to technology management and coordinates the interaction
     of all technology devices
Operating system software - supports the application software and manages how the hardware
     devices work together
Utility software - provides additional functionality to the operating system
Software contains the instructions that the hardware executes to perform an information processing
task
Without the aid of software, the computer hardware is useless
Two categories of software
     Application
     System
 
Application Software
Application software is used for specific information processing needs, including:
Payroll
Customer relationship management
Project management
Training
Word processing and many others
Personal productivity software :
used to perform personal tasks such as writing a memo, creating a graph, or creating a slide
presentation
Examples:
Microsoft Word
Microsoft Excel
Internet Explorer
 Quicken
 
Application Software (Continued)
Vertical market software :
application software that is unique to a particular industry
Patient-scheduling software
Nursing allocation software
Horizontal market software :
general enough to be suitable for use in a variety of industries
Inventory management software
Payroll software
 
System Software
System software controls how the various technology tools work together along with the application
software
Operating System controls application software and manages how the hardware devices work
together
Example: Microsoft Windows XP Home,
 Mac OS, Linux
Utility
Uninstaller software, spyware software