UNIT-1
Data
Data is raw facts that cannot give meaning on its own. It is a representation of what we see and perceive using things like
letters and numbers. Facts such as 100, 250, age, and Ethiopia are considered as data. Each of them does not give meaning on
its own. For example, 100 can be the weight of a person or the measurement of a distance. Likewise, the word Ethiopia can
be a country name or a person’s name. It does not tell us any meaning unless it is related to other data. Data is recorded and
stored using numbers, texts, and images. Some data can be represented better by numbers than texts. For example, age is
better represented by numbers than texts. Likewise, words such as name are only represented by text. With the development
of satellite technology, representation of data in the form of image has become very popular. Thus, one form of data
representation is better than the other forms of representation, depending on the type of data and context.
Information
Information is data processed in a meaningful way to the end users. Registering daily sales data may not give meaning. But
when we aggregate daily sales data by weeks of the month, it becomes information as it shows whether the sales are
increasing or decreasing. By asking relevant questions about ‘who’, ‘what’, ‘when’, ‘where’, etc., we can derive valuable
information from the data and make it more useful for users. Therefore, information is a processed data that is used to
answer certain questions. Like data, information can be also represented in different forms. It can be
represented in the form of a table, line graph, bar graph & etc.
Knowledge
Knowledge is an understanding which is acquired by further processing and integrating different sets of information. It
includes both understanding and skill. For example, when you tell a child how to ride a bicycle, you are giving information.
This helps the child to understand how to ride a bicycle. When a child applies the information in riding a bicycle, the child
acquires the skills necessary to properly ride a bicycle. Then the information becomes knowledge.
Wisdom
Wisdom is the ability to make wise decisions and judgments using one’s knowledge. It is the highest level of human
understanding. Wisdom is like love, intelligence, and politeness in that it is a good thing to have. The more we have it, the
better we become.
UNIT-2
Artificial Intelligence
Artificial Intelligence (AI) is a branch of computer science that deals with the design of systems that mimic human
intelligence. AI systems are designed to have features that only humans are capable of such as reasoning and generalization.
An example of reasoning is, “My friend is either at home or in her workplace. My friend is not in her workplace. Therefore,
my friend is at home”. Generalizing is about applying past experiences to current problems of similar nature. For example, “I
know how to change a wheel on my bicycle and therefore I can use this knowledge to change the wheel on my friend’s
bicycle.”
Even though the history of AI goes back to the 1940s, it was in the 1950s that the term was coined. AI has become so
popular and a powerful tool today due mainly to significant growth in computer capacity and the availability of a large
amount of data. AI algorithms are now extensively used in a wide range of areas including business, medicine, and
entertainment.
Branches of AI:- though there is no hard and fast way of identifying the subfields of AI, the following groups can be
considered as branches of AI.
a. Machine Learning
Machine Learning is the study of computer algorithms that enable the computer to learn from data and improve itself
without being explicitly programmed. Machine learning algorithms learn from experience. Unlike conventional
computer algorithms with explicit instructions that are followed by the computer to solve a problem, machine
learning algorithms allow the computer to train on sample data inputs. A model that is built from the sample data
will then be used to make predictions that are useful for decision-making. Fraud detection, recommendation systems,
email spam detector, and speech recognition are some of the examples of applications of machine learning.
b. Robotics
Robotics is the study of machines called robots that substitute tasks that are traditionally done by human beings.
Over the past few decades, robots have been used mainly in replacing human labor in routine and mundane activities
such as those that are found in car manufacturing assembly lines. Robots are also used in environments that are
considered hazardous to human beings like handling radioactive wastes, underwater, and space explorations.
c. Natural Language Processing
Natural Language Processing (NLP) is a branch of AI that deals with enabling computers to understand written and
spoken human language in the same way human beings do. Computers’ understanding of natural language is what
powers the services we get from a wide range of systems around us. Some of the major
application areas of NLP are listed below.
• Spam Detection
• Machine Translation
• Virtual Assistant
• Sentiment Analysis
• Fake News Identification
• Text Summarization
d. Expert Systems
Expert systems are computer programs that emulate human experts. They are designed to solve problems that are normally
solved by human experts. Expert systems are one of the earliest attempts to put the field of artificial intelligence to the test.
Some of the fields that benefit from expert systems include medical
diagnosis, petroleum engineering, and financial investing. An expert system consists of three components: User Interface, &
Knowledge Base.
Augmented Reality
Augmented Reality (AR) is a technology that enhances the real world by overlaying computer-generated digital data on real-
world objects. By blending the real world with computer-generated information, AR creates an engaging and dynamic user
experience. The hardware of AR includes a processor, sensors, input devices, and a display. Mobile devices do have all four
components to run AR applications. Depending on the application, however, the display could be tablets, smartphones, head-
mounted displays (HMD), or smart glasses. Such displays are used to locate objects of focus
as well as show the computer-generated overlaid information.
AR works by first capturing the picture of the real-world object through a camera. Then relevant information about the
image like measurement of the object, as well as other objects that are present in the image and their relative distance from
the object in focus, will be processed by the software. Virtual information will be finally generated and overlaid on the
object.
Virtual Reality
Virtual reality (VR) is a technology that creates a three-dimensional computer generated simulated environment. A person
can interact with VR using electronic devices such as goggles, headsets, gloves, or bodysuits. VR attempts to create an
illusory environment that can be presented to our senses with artificial information, making our minds believe that it is
(almost) a reality. Unlike AR, VR creates a completely immersive experience for the user.
Using sensors of various types, a VR environment responds to the user’s movements and adjusts views and perspectives in
real-time. VR also enables users to touch and manipulate virtual objects by way of data gloves equipped with force-feedback
devices. This is how a VR creates the illusion of being in a real environment.
UNIT-3
Introduction SQL
SQL is a language to operate databases; it includes database creation, deletion, fetching rows, modifying rows, etc. SQL is
an ANSI (American National Standards Institute) standard language, but there are many different versions of the SQL
language.
What is SQL?
SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in a
relational database.
SQL is the standard language for Relational Database System. All the Relational Database Management Systems (RDMS)
like MySQL, MS Access, Oracle, and SQL Server use SQL as their standard database language.
SQL is widely popular because it offers the following advantages −
· Allows users to access data in the relational database management systems.
· Allows users to describe the data.
· Allows users to define the data in a database and manipulate that data.
· Allows embedding within other languages using SQL modules, libraries & pre-compilers.
· Allows users to create and drop databases and tables.
· Allows users to create view, stored procedure, functions in a database.
· Allows users to set permissions on tables, procedures and views.
What is a table?
The data in an RDBMS is stored in database objects which are called as tables. This table is basically a collection of related
data entries and it consists of numerous columns and rows.Remember, a table is the most common and simplest form of data
storage in a relational database. The following program is an example of a
CUSTOMERS table −
+----+----------+-----+-----------+----------+
| ID | NAME | AGE | ADDRESS | SALARY |
+----+----------+-----+-----------+----------+
| 1 | Robel Belay | 32 | Hawassa| 20000.00 |
| 2 | Kasu Gosa | 25 | Dilla | 15000.00 |
| 3 | Rahel Shewa | 23 | Addis Abeba | 9000.00 |
| 4 | Rodas Hussen | 25 | Gonder | 1200.00 |
| 5 | Yonas Mamo | 27 | Arbegona | 8500.00 |
+----+----------+-----+-----------+----------+
What is a field?
Every table is broken up into smaller entities called fields. The fields in the CUSTOMERS table consist of ID, NAME,
AGE, ADDRESS and SALARY.
A field is a column in a table that is designed to maintain specific information about every record in the table.
What is a Record or a Row?
A record is also called as a row of data is each individual entry that exists in a table. For example, there are 5 records in the
above CUSTOMERS table. Following is a single row of data or record in the CUSTOMERS table −
+----+----------+-----+-----------+----------+
| 1 | Robel Belay | 32 | Hawssa | 20000.00 |
+----+----------+-----+-----------+----------+
A record is a horizontal entity in a table.
What is a column?
A column is a vertical entity in a table that contains all information associated with a specific field in a table.
For example, a column in the CUSTOMERS table is ADDRESS, which represents location description and would be as
shown below –
+-----------+
| ADDRESS |
+-----------+
| Hawassa |
| Dilla |
| Addis Abeba |
| Gonder |
| Arbegona |
What is a NULL value?
A NULL value in a table is a value in a field that appears to be blank, which means a field with a NULL value is a field with
no value.
It is very important to understand that a NULL value is different than a zero value or a field that contains spaces. A field
with a NULL value is the one that has been left blank during a record creation.
SQL Constraints
Constraints are the rules enforced on data columns on a table. These are used to limit the type of data that can go into a
table. This ensures the accuracy and reliability of the data in the database.
Constraints can either be column level or table level. Column level constraints are applied only to one column whereas,
table level constraints are applied to the entire table.
Following are some of the most commonly used constraints available in SQL −
NOT NULL Constraint − Ensures that a column cannot have a NULL value.
DEFAULT Constraint − Provides a default value for a column when none is specified.
UNIQUE Constraint − Ensures that all the values in a column are different.
PRIMARY Key − Uniquely identifies each row/record in a database table.
FOREIGN Key − Uniquely identifies a row/record in any another database table.
CHECK Constraint − The CHECK constraint ensures that all values in a column satisfy certain conditions.
INDEX − Used to create and retrieve data from the database very quickly.
UNIT-4
WEB DEVELOPMENT
World Wide Web (www), commonly known as the Web, is one of the most important services of the Internet. The Internet is a
network of networks that the Web runs on. The Web is just one of the services of the Internet, and the most popular one. There
are also many other services that are provided over the Internet such as email, file transfer and communication services. W
The Web is a collection of websites or webpages that are accessed over the Internet using a web browser. Tim
Berners-Lee invented the Web in 1989 in the famous laboratory found in Switzerland known as CERN. When the
Web was invented, it was formed out of four essential foundations: HTML, HTTP, a web server, and a web browser.
HTML, which stands for Hyper Text Markup Language, is the language that is used to create webpages. A web
browser is software used by users to view webpages. A web server, on the other hand, is software that stores webpages
and responds to user requests that come through web browsers. HTTP, which stands for Hyper Text Transfer Protocol,
is the set of rules that web browsers and web servers use to communicate with each other. A website is a publicly
accessible collection of interrelated webpages. Hypertext is used to link a webpage with other resources like another
webpage, videos, images, and the like. A website that is physically placed in one part of the world can be accessed
from any other part of the world. It is also how online transactions are conducted by e-commerce companies.
Today, shoppers use websites to make orders of different types of products from their homes or workplaces. This
avoids the need to physically go to shops, which reduces the cost of transportation and increases the efficient use
of our limited time. Similarly, various government e-services are accessed through websites.
Web development is the actual creation or building of websites while website design deals with defining the layout
and overall look of the website. Websites can be developed using a WYSIWYG (What you see is what you get)
software like Adobe Dreamweaver. Simple text editors such as Notepad are the other alternative software to develop
websites. Though developing webpages using simple text editors is a little more difficult than WYSIWYG software,
it is more effective in enabling the learner to master the language.HTML Basics
HTML is a markup language that is used to create webpages. The different elements of a webpage such as headings,
tables, paragraphs, images, and others are defined using the predefined set of markup tags of HTML.
HTML documents can be prepared using simple text editor software such as Notepad. The documents are saved with
a “.html” extension. For example, home.html is a valid file name for an HTML document or a webpage.
HTML tags are a set of predefined names enclosed in angle brackets. Each HTML tag has its specific meaning, and
web browsers are designed to interpret or render HTML tags according to their intended purposes.
Sample HTML tags and their meanings are shown in Table
Tag Name Meaning
<!DOCTYPE html> Every html document must began with this
<p> Paragraph
<i> Italic
<h1> upto <h6> Heading size
<li> list
<ol> Order list
<html> Represent the root element
< title> Defines a title for the document & very important for Search Engine
Optimization (SEO)
<body> represents the content of an html document
<main> the main tag specifies the main content of a document
<address> The address tag defines the contact information
All HTML documents or webpages have a common structure. What changes from one webpage to another is what
goes inside the <body> and the <head> sections of HTML documents.
HTML attributes are used to define more properties to HTML elements. HTML paragraphs, for example, are left-
aligned by default. However, if a paragraph is needed to be presented with the texts aligned to the right, the “align”
attribute should be used. Attributes are written inside the start tag with attribute-value pairs.
Attributes are normally optional to many of the HTML tags. However, there are some HTML elements that cannot
function as intended without the use of some attributes. The <img> HTML element is one such example. The <img>
element should have the “src” attribute, which refers to the name and location of the actual
image that is required to be inserted into the webpage. The other HTML element that uses the “src” attribute is the
<video> element. <video> element is used to add a video to a webpage.
HTML links are used to navigate from one webpage to another or from one part of a webpage to another. The links
could come in the form of text or images and are normally known as hyperlinks. Hyperlinks can easily be
distinguished by the hand symbol that the mouse cursor is turned to when the mouse is hovering over
the hyperlinks. The anchor tag (<a>) is used to create hyperlinks. An HTML element that is formed
from an anchor tag has the following format:
The example shows how a link to Google is created and what the hyperlink looks like when it is displayed on the web
browser.
