Upload
raghu-venkata
View
232
Download
0
Embed Size (px)
Citation preview
7/30/2019 ITIS- Components of IT
1/60
1
Components OfInformation Technology
Dr. Gita A. KumtaSchool of Business Management
NMIMS (Deemed University)
7/30/2019 ITIS- Components of IT
2/60
What is a Computer?
An electronic device that stores, retrieves,
and processes data, and can be programmed with
instructions.
A computer is composed of hardware and
software,
Can exist in a variety of sizes and configurations.
7/30/2019 ITIS- Components of IT
3/60
Types of Computers
Mini and Mainframe Computers
Very powerful, used by large organisations such as
banks to control the entire business operation.
Personal Computers
Cheap and easy to use. Often used as stand-alone
computers or in a network. May be connected to largemainframe computers within big companies.
7/30/2019 ITIS- Components of IT
4/60
Packaging the Computer
The many physical forms of the
general purpose computer
All follow general organization:
Primary memory
Input units
Output units
Central Processing Unit
Super Computers
Mainframe Computers
Minicomputers
Microcomputer
Palmtop Computer
Calculator
Fast Expensive Complex Large
Slow Cheap Simple Small
7/30/2019 ITIS- Components of IT
5/60
Basic Concepts of Computer
Hardware The term hardware refers to the physical components of your
computer such as the system unit, mouse, keyboard, monitor etc.
Input / Output (I/O): Refers to the process of getting
information into and out of the computer.
Input: Those parts of the computer receiving information to
programs.
Output: Those parts of the computer that provide results of
computation to the person using the computer.
7/30/2019 ITIS- Components of IT
6/60
Computer System
Cont.
7/30/2019 ITIS- Components of IT
7/60
The Central Processing Unit
The Central Processing Unit ( CPU)
Often referred to as the brain of the
computer.
Responsible for controlling all activities of thecomputer system.
Motherboard: The place where most of
the electronics including the CPU aremounted.
7/30/2019 ITIS- Components of IT
8/60
Major Components of CPU
The three major components of the CPU are:
Arithmetic Unit (Computations performed)
Accumulator (Results of computations kept here)
Control Unit (Has two locations where numbers
are kept)
Instruction Register (Instruction placed here for
analysis) Program Counter (Which instruction will be performed
next?)
Instruction Decoding Unit (Decodes the instruction)
7/30/2019 ITIS- Components of IT
9/60
7/30/2019 ITIS- Components of IT
10/60
Input Devices
Connecting Hardware to the computer
Hardware needs access through some general
input/output connection.
Port: The pathway for data to go into and out of the
computer from external devices such as keyboards.
There are many standard ports as well as custom
electronic ports designed for special purposes.
Ports follow standards that define their use. SCSI, USB: Multiple peripheral devices (chain).
RS-232, IDE: Individual peripheral devices.
7/30/2019 ITIS- Components of IT
11/60
Input Devices
How to tell it what to do and capture input?
Two categories of input hardware:Those that deal with original data.
Those that handle previously stored data.
7/30/2019 ITIS- Components of IT
12/60
Input Devices
Input hardware: Those that deal with originaldata.
Keyboard
MouseVoice recognition hardware
Scanner
Digital camera
Digitizing: The process of taking a visual
image, or audio recording and converting it to a
binary form for the computer.
7/30/2019 ITIS- Components of IT
13/60
Input / Output DevicesCategory Name of the Device
Keying Device Keyboard
Punch Card Reader
Pointing Device Mouse
Touch Screen
Joy Stick
Light Pen
Optical Character Recognizer Bar Code Reader
Optical Character Reader
Other Devices Cameras
Digitizers ( for maps a, graphs etc )
Smart Cards
Telephone
Output Devices Printer, Plotter, Fax, Monitor
7/30/2019 ITIS- Components of IT
14/60
Input Devices
Peripheral device: A piece of hardware
like a printer or disk drive, that is outside
the main computer Hardware needs software on the computer
that can service the device.
7/30/2019 ITIS- Components of IT
15/60
Input Devices
Basic Technologies for Storing
Common Basic Technologies for Storing
Binary Information:
Electronic
Magnetic
Optical
7/30/2019 ITIS- Components of IT
16/60
Input Devices
Electronic Circuits Most expensive of the three forms for
storing binary information.
A flip-flop circuit has either one electronic
status or the other. It is said to flip-flop from
one to the other.
Electronic circuits come in two forms:
Permanent
Non-permanent
7/30/2019 ITIS- Components of IT
17/60
7/30/2019 ITIS- Components of IT
18/60
Input Devices
Optical
Uses lasers to read the binary information
from the medium, usually a disc. Millions of tiny holes are burned into the surface of
the disc.
The holes are interpreted as 1s. The absence of holes are
interpreted as 0s.
7/30/2019 ITIS- Components of IT
19/60
Secondary Memory Input Devices
These input devices are used by a computer to storeinformation and then to retrieve that information as
needed.
External to the computer.
Commonly consists of floppy disks, hard disk drives, or
CD-ROMs.
Secondary memory uses binary.
The usual measurement is the byte. A byte consists of 8 binary digits (bits). The byte is a
standard unit.
7/30/2019 ITIS- Components of IT
20/60
Storage Devices
How it saves data and programs for retrieval? The four most important characteristics of
storage devices:
Speed and access timeCost / Removable versus non-removable
Capacity
Type of access
7/30/2019 ITIS- Components of IT
21/60
Storage Devices
Speed (Access time) - How fast information
can be taken from or stored onto the
computer memory devices medium.
Electronic circuits: Fastest to access.
40 billionths of a second.
Floppy disks: Very slow in comparison.
Takes up to 1/2 second to reach full speed beforeaccess is even possible.
7/30/2019 ITIS- Components of IT
22/60
7/30/2019 ITIS- Components of IT
23/60
Storage Devices
Type of Access
Sequential - Obtained by proceeding
through the storage medium from the
beginning until the designated area isreached (as in magnetic tape).
Random Access - Direct access (as in
floppy and hard disks).
7/30/2019 ITIS- Components of IT
24/60
Output Devices
How it shows you what it is doing / done?
Monitor
The monitor (the screen) is how the computer sendsinformation back to you.
Printer
A printer is also an output device. There are many differenttypes of printers. In large organizations laser printers are used
as they can print very fast and give a very high quality output.
7/30/2019 ITIS- Components of IT
25/60
Output Devices
Storage Requirements: How much storage
capacity is needed for One keystroke on a keyboard. 1 byte (8 bits)
One page single-spaced document. 4.0 K
Storage Capacity: How much data can be
stored on One inch of 1/2 in. wide magnetic tape. 4 K
One DVD. up to 17 GB
7/30/2019 ITIS- Components of IT
26/60
Output Devices
Plotters
A plotter is an output device similar to a printer,
but normally allows you to print larger images.
SpeakersEnhances the value of educational and presentation
products.
Speech synthesisersGives you the ability not only to display text on a
monitor but also to read the text to you.
7/30/2019 ITIS- Components of IT
27/60
Software
The software is a set of programmes, datastructures and documentation.
Programmes are a set of instructions that
makes the computer work with data.
Software is held either on your computers hard
disk or a storage device and copied into the
RAM (Random Access Memory) as and whenrequired.
7/30/2019 ITIS- Components of IT
28/60
Types of Software
System Software
Application Software
Business Application Software
7/30/2019 ITIS- Components of IT
29/60
System Software
Controls various internal computer
activities.
Covers the following categories:
Operating system,Utility software
Data Base Management System.
Device driver that will allow thecomputer to communicate with a
particular device.
7/30/2019 ITIS- Components of IT
30/60
7/30/2019 ITIS- Components of IT
31/60
Application Software
Used to perform specialized functions or
specific jobs.
Specific jobs might be to create a family tree,
learn basic math, create a plot for a novel, do
payroll and accounting, collect payment, or
draw flowcharts.
Users can choose from thousands of
applications to facilitate the job.
7/30/2019 ITIS- Components of IT
32/60
Cont.
Type Software
Word Processing Microsoft WordCorel Word Perfect
Spreadsheet Microsoft Excel , Open Office /
Star Office
Graphics Adobe Macromedia
Desktop Publishing Corel
Major Categories of
Application Software
7/30/2019 ITIS- Components of IT
33/60
Business Application Software
Software that enables Business functions.
From a batch process to on-line, real-time.
Billing system, inventory system, accounting.
Enterprise Resource Planning System
Data Warehousing
Business Intelligence
7/30/2019 ITIS- Components of IT
34/60
Programming Languages
Various methods of writing computer
instructions.
Instructions adhere to a particular set ofprotocols for each language.
Regardless of which language a program
was written in, a computer can only
process binary code.
7/30/2019 ITIS- Components of IT
35/60
Generations of Computer Languages
First generation of computer languages wasmachine language.
Second generation is assembly language
developed in the 1950s.
Third generation (3GL) languages, called
high-level languages.
Fourth generation (4GL) languages, called
very high-level languages which rely onobjects of code that are reusable.
7/30/2019 ITIS- Components of IT
36/60
Information:
Refers to data that is viewed in some context. May involve some processing also, e.g., a list of month-
wise sales with the total yearly sales calculated. Information helps the user reveal trends or patterns in the
data.
Database:
It is a shared and organized collection of logically relevantdata designed to meet the information needs of multiple users
in an organization, e.g., a database of all the addresses.
Database Concepts
7/30/2019 ITIS- Components of IT
37/60
7/30/2019 ITIS- Components of IT
38/60
Data Versus Information
Monthly Sales Report
for West Region
Sales Rep: Charles Mann
Emp No. 79154Item Qty Sold PriceTM Shoes 1200 $100
7/30/2019 ITIS- Components of IT
39/60
Logical Data Elements
NameField
PayrollRecord
PayrollFile/Table
PersonnelDatabase
7/30/2019 ITIS- Components of IT
40/60
Views of Data
There are different ways in which we can
view the data.
A database system typically has two levelsof abstraction of data:Physical level: Describes how a record (e.g., a
customer) is physically stored on the computer
Logical level: Describes data stored in thedatabase and the relationships among them,
7/30/2019 ITIS- Components of IT
41/60
Data Modeling
Analysis of data objects that are used in a
business or other context and the identification
of the relationships among these data objects.
Is a collection of logical constructs used to
represent the data structure & the data
relationships found within the database.
7/30/2019 ITIS- Components of IT
42/60
Categories of Data Models
Conceptual models Focus on the logical nature of the data representation.
Concerned with what is represented rather than how it is
represented.
Entity-Relationship Diagram (ERD) is a popular conceptualmodel.
Implementation models Place the emphasis on how the data are represented in the
database : Hierarchical, Network, Relational, Object-oriented.
7/30/2019 ITIS- Components of IT
43/60
Hierarchical Model
In 1966, IBM released the first commercially availableDBMSIMS (Information Management System) based on
the hierarchical data model. The basic structure of this
model is:
Collection of records is logically organized to conform to
the upside-down tree (hierarchical) structure. The top layer is perceived as the parent of the segment
directly beneath it.
The segments below other segments are the children of the
segment above them. A tree structure is represented as a hierarchical path on the
computer's storage media.
7/30/2019 ITIS- Components of IT
44/60
Network Model
General Electric (GE) developed a DBMS calledIDS (Integrated Data System) based on the
network data model in 1967.
In this model, a relationship is called a set.
Each set is composed of at least two record types:
an owner (parent) record and a member (child)
record.
A set represents a 1:M relationship between the
owner and the member.
7/30/2019 ITIS- Components of IT
45/60
Network DBMS
7/30/2019 ITIS- Components of IT
46/60
DBMS between the Database and the End Users
7/30/2019 ITIS- Components of IT
47/60
Data Dictionary Management
A data dictionary (or metadata) is the collection ofdescriptions of the data objects or items in a data
model for the benefit of the programmers and others
who need to refer to them.
Data storage management Data transformation and presentation
Security management
Multi-user access control
Backup and recovery management
Data integrity management Database access languages and application programming interfaces
Database communication interfaces.
7/30/2019 ITIS- Components of IT
48/60
Sources of Data for the Computer
Two types of data stored within a computer: Original data orinformation: Data being introduced to a
computing system for the first time.
Computers can deal directly with printed text, pictures,
sound, and other common types of information.
Previously stored data orinformation: Data that has already
been processed by a computer and is being stored for later use.
These are forms of binary data useful only to the computer.
Examples: Floppy disks, DVD disks, and music CDs.
7/30/2019 ITIS- Components of IT
49/60
Moving Information
Within the Computer How do binary numerals move into, out of,
and within the computer?
Information is moved about in bytes, ormultiple bytes called words.
Words are the fundamental units of information.
The number of bits per word may vary per
computer.
A word length for most large IBM computers is 32
bits:
7/30/2019 ITIS- Components of IT
50/60
A network provides the following major
benefits:
Simultaneous (or concurrent) access tocritical program and data
Sharing of peripheral devices (e.g.,
printers) Streamlined personal communications
Easier back-up processes.
Networking Concepts
7/30/2019 ITIS- Components of IT
51/60
Any network can be studied in either of the following ways:
LAN
WAN
MAN
Geography
Bus
Star
Ring
Mesh
Server-based
Client/server
Peer-to-peer
Interactions
Network Design
Topology
7/30/2019 ITIS- Components of IT
52/60
Types Of Networks
LANLocal Area Network
Is a small Geographical area such as Institute.
MANMetropolitan Area Network
Is a network over a larger geographical area such as the
provincial government.
WANWide Area Network
Is a network used over an extremely large geographicalarea such as the federal government.
7/30/2019 ITIS- Components of IT
53/60
Bus Topology
Allows information to be directed from one computer to the other.
7/30/2019 ITIS- Components of IT
54/60
Is the most common type used.
All computers are attached to a hub.
Less collisions and most efficient.
Star Topology
7/30/2019 ITIS- Components of IT
55/60
Uses a token to pass information from one computer to
the other.
A token is attached to the message by the sender to
identify which computer should receive the message. As the message moves around the ring, each computer
examines the token. If the computer identifies the token
as its own, then it will process the information.
If one computer is broken or down, the message cannotbe passed to the other computers.
Ring Topology
7/30/2019 ITIS- Components of IT
56/60
Ring Topology
7/30/2019 ITIS- Components of IT
57/60
Mesh Topology
A network setup where each of the computers andnetwork devices are interconnected with one
another
Allows most transmissions to be distributed, even
if one of the connections go down.
Not commonly used for most computer networks
as it is difficult and expensive to have redundant
connection to every computer. Commonly used for wireless networks.
7/30/2019 ITIS- Components of IT
58/60
Mesh Topology
7/30/2019 ITIS- Components of IT
59/60
7/30/2019 ITIS- Components of IT
60/60
Syntax
Structure or format of the data
Indicates how to read the bits - field delineation
Semantics
Interprets the meaning of the bits
Knows which fields define what action
Timing
When and what data should be sent. Speed at which data should be sent or speed at
which it is being received.
Elements of a Protocol