First information based series on Information technology covering topics like IT, Computer Usage, Data Storage, Types of computers, computer hardware, computer software, computer firmware, enterprise storage & more.

4. enables a computer to store, at least temporarily,data and programs.
allows a computer to permanently retain large amounts of data. Common mass storage devices
include solid state drives (SSDs) or disk drives and tape drives.
usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a
computer.
a display screen,printer,or other device that lets you see what the computer has accomplished.
the heart of the computer,this is the component that actually executes instructions.

5. Personal computer: a small, single-user computer based on a microprocessor.In addition to the microprocessor,a
personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving
data.
Workstation: a powerful,single-user computer.A workstation is like a personal computer,but it has a more powerful
microprocessor and a higher-quality monitor.
Minicomputer: a multi-user computer capable of supporting from 10 to hundreds of users simultaneously.
Mainframe: a powerful multi-user computer capable of supporting many hundreds or thousands of users
simultaneously.
Supercomputer: an extremely fast computer that can perform hundreds of millions of instructions per second.

6. Hardware
Hardware refers to the physical elements of a computer. This is also sometime called the machinery or the equipment of
the computer. Examples of hardware in a computer are the keyboard, the monitor, the mouse and the central
processing unit. However, most of a computer's hardware cannot be seen; in other words, it is not an external element
of the computer, but rather an internal one, surrounded by the computer's casing (tower). A computer's hardware is
comprised of many different parts, but perhaps the most important of these is the motherboard. The motherboard is
made up of even more parts that power and control the computer.
In contrast to software, hardware is a physical entity. Hardware and software are interconnected, without software, the
hardware of a computer would have no function. However, without the creation of hardware to perform tasks directed
by software via the central processing unit, software would be useless.
Hardware is limited to specifically designed tasks that are, taken independently, very
simple. Software implements algorithms (problem solutions) that allow the computer to
complete much more complex tasks.

7. Software
Software, commonly known as programs or apps, consists of all the instructions that tell the hardware how to perform
a task.These instructions come from a software developer in the form that will be accepted by the platform (operating
system + CPU) that they are based on. For example, a program that is designed for theWindows operating system will
only work for that specific operating system.Compatibility of software will vary as the design of the software and the
operating system differ.Software that is designed forWindows XP may experience a compatibility issue when running
underWindows 2000 or NT.
Software is capable of performing many tasks, as opposed to hardware which can only perform mechanical tasks that
they are designed for. Software provides the means for accomplishing many different tasks with the same basic
hardware. Practical computer systems divide software systems into two major classes:
System software: Helps run the computer hardware and computer system itself. System software includes operating
systems, device drivers,diagnostic tools and more. System software is almost always pre-installed on your computer.
Application software: Allows users to accomplish one or more tasks. It includes word processing, web browsing and
almost any other task for which you might install software. (Some application software is pre-installed on most
computer systems.)
Software is generally created (written) in a high-level programming language, one that is (more or less) readable by
people.These high-level instructions are converted into "machine language" instructions, represented in binary code,
before the hardware can "run the code".When you install software, it is generally already in this machine language,
binary, form.

8. System software on right.Applications on left. More
system and application software is indicated in the
tray at the bottom
Diagrammatic view of a very simple
decision algorithm that could be
programmed

9. Firmware
Firmware is a very specific, low-level program for the hardware that allows it to accomplish some specific task.
Firmware programs are (relatively) permanent,i.e., difficult or impossible to change. From the higher-level view
of software, firmware is just part of the hardware, although it provides some functionality beyond that of simple
hardware.
Firmware is part of devices (or device components) such as a video card,
sound card, disk drive and even the motherboard.
ROM BIOS chip holding firmware used to boot the computer Analogy with autopilot as firmware

10. Computer data storage, often called storage or memory, is a
technology consisting of computer components and recording
media used to retain digital data. It is a core function and fundamental
component of computers.
In a computer,data storage is the place where data is held in an
electromagnetic or optical form for access by a computer processor
(A processor is the logic circuitry that responds to and processes the
basic instructions that drive a computer.The four primary functions of
a processor are fetch,decode, execute and writeback.)
Storage is frequently used to describe the devices and data connected
to the computer through input/output (I/O) operations -- that is, hard
disk and tape systems and other forms of storage that don't include
computer memory and other in-computer storage. For the enterprise,
the options for this kind of storage are of a much greater variety and
expense than those related to memory.

11. Enterprise data storage is often classified as primary and secondary storage, depending on how the data is used and
what type of media it is placed on.
Primary storage holds data in memory (sometimes called random access memory or RAM) and other built-in devices,
such as the processor's L1 cache.Secondary storage commonly includes data on hard disks, tapes and other devices
requiring I/O operations. Secondary storage media is often used in cloud storage.
Primary storage is much faster to access than secondary storage because of the proximity of the storage to the
processor and the nature of the storage devices.On the other hand, secondary storage can hold much more data than
primary storage.
Antiquated terms for primary and secondary storage are main storage and auxiliary storage,respectively.To add to the
confusion, there is an additional meaning for primary storage that distinguishes actively used storage from backup storage.
Types of storage
There are many types of data storage, with various levels of capacity and speed.These include magnetic tape; magnetic
disks; optical discs, such as CDs, DVDs and Blu-ray disks; flash memory;main memory (dynamic RAM);and cache
memory.

12. Measuring storage
Bits and bytes are the basic measurements for computer storage. One single binary value (1 or 0) makes up a bit, and
eight bits make up one byte. Other capacity measurements --and their abbreviations -- to know are:
kilobyte (KB) equal to 1,024 bytes
megabyte (MB) equal to 1,024 KB
gigabyte (GB) equal to 1,024 MB
terabyte (TB) equal to 1,024 GB
petabyte (PB) equal to 1,024 TB
exabyte (EB) equal to 1,024 PB
It's still rare for a single storage system or connected system to reach an EB of data, but there are now storage systems
built to store PBs.