"Computer" is an "electronic device" that has become a useful device in our day to day life. Following are the areas where in computer are useful to us:

i) Information: help access internet through which we are able to access information around the globe.

ii) Entertainment: Various social media sites provide content for entertainment. Also, we have online TV series and movies that can be accessed by computer.

iii) Bill Payments: One can easily pay bills online with help of internet and saves time of physically going to the office and paying it.

iv) Ticket Reservation: Flight, railway and bus tickets can be reserved via internet.

Computer hardware is the collection of physical parts of a computer system. This includes the computer case, monitor, keyboard, and mouse. It also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many others.

Computer software is a collection of programs, procedure and related data that provide the instructions for telling a computer what to do and how to do it.

• A motherboard
• A Central Processing Unit (CPU)
• A Graphics Processing Unit (GPU), also known as a video card
• Random Access Memory (RAM), also known as volatile memory
• Storage: Solid State Drive (SSD) or Hard Disk Drive (HDD)

In terms of construction, each of these main components are attached to the motherboard and then put into a protective case—resembling the clean, polished look most of us are accustomed to seeing. 

Computer Program set of instructions that directs a computer to perform some processing function or combination of functions. For the instructions to be carried out, a computer must execute a program, that is, the computer reads the program, and then follows the steps encoded in the program in a precise order until completion.

Contemporary computers can be categorized as mainframes, midrange computers, PCs, workstations, and supercomputers. Managers need to understand the capabilities of each of these types of computers, and why some types are more appropriate for certain processing work than others. There are five main ones: supercomputers, mainframe computers, minicomputers, microcomputers, and finally mobile computers.

• The computer is considering an important part in these days which helps to save time and complete work faster.
•  In a fraction of time, it finishes complex mathematical chores.
• Strengths of using a computer are speed, high storage capacity, versatility, accuracy, and reliability.
•  The weakness of computer is zero IQ and lacking decision making.

Weaknesses of Computers :-

Lack of Decision-Making Power :-

Computers can not decide their own. They do not posses this power which is a great asset of human being.

IQ Zero :-

Computers are dummb machines with Zero IQ. They need to be told each and every step, however minute it may be.

No Heuristics :-

Heuristics means learning from the past experiences. If a computer commits an error once and similar situation/event occurs again, computer will commit the same error again.

 RAM—Random Access Memory: As the name suggests, any data from any location in RAM can be accessed at any time. The time taken to access any location is the same. RAM is read/write memory. We can read data from RAM and we can write data on RAM. Read process is non-destructive i.e., if we read data from a location, it still remains in the location. Write process is destructive i.e., if we write data in a memory location which already has some data stored in it, the previous data disappears and is replaced by the new data. RAM is volatile. Whenever the power is switched off, anything and everything stored in RAM vanishes. This is the reason why we call RAM a temporary memory. While buying a computer, the capacity of its RAM is important to be kept in mind. Nowadays personal computers upto 16 GB RAM are available.

A presentation software is a computer software package used to show information, normally in the form of a slide show. It mostly includes three major functions: an editor that allows text to be inserted and formatted, a method for inserting and manipulating graphic images and a slide-show system to display the content.

RAM Full Form - Random Access Memory.

Cyber safety is the safe and responsible use of information and communication technology. It is about keeping information safe and secure, but also about being responsible with that information, being respectful to other people online, and using good Internet etiquette. It includes body of technologies, processes and practices designed to protect networks, computers, programs and data from attack, damage or unauthorized access

In the field of entertainment, computers are used for making animation 1:photoshop 2:animation software 3:MS word 4:none of these

Ans : animation software

Wireless Networking Technology
It is the future of computer and Internet connectivity. The data is transmitted in air through microwave and other radio signals. Since no wires are used, so data can be sent overseas easily, efficiently and more reliably. Cellular phones are part of huge wireless network system. Police department and other security agencies use wireless network to communicate important messages. In areas where the telecom infrastructure is not proper, Internet access can be provided using wireless technology. But some disadvantages are also attached to this networking such as:
(i) Wireless networks are little slower than network connected by ethernet cables.
(ii) The signals are more susceptible to errors since anyone can break into the signal.
(iii) A major issue is compatibility of different components being networked which might require an extra effort.
(iv) Some people are of the view that excess of microwave radiation might cause some health hazards in near future.
 

A group of autonomous computers and associated devices connected together by communication channels like cables or telephone lines etc. is called a network.
In a network, the computers work as stand alone machines but can communicate with other computers on the network as and when required.

CBSE Notes for Class 9 Foundation of Information Technology – Computer Networking

CBSE Notes for Class 9 Foundation of Information Technology – Computer Networking

The last century was the century of Information Technology revolution. With the great breakthrough in the world of communication by the use of worldwide network of telephone lines, satellite launching and computers, the world has come very close. Sending a letter by post is virtually becoming obselete. Now is the time of e-mail, chats and video conferencing. All this has become possible because of networking.

NETWORK
A group of autonomous computers and associated devices connected together by communication channels like cables or telephone lines etc. is called a network.
In a network, the computers work as stand alone machines but can communicate with other computers on the network as and when required.

Types of Networks
There are mainly three types of networks as discussed below:
1. LAN (Local Area Network): A network spread over a diameter of minimum 1 m to maximum 10 km is called a local area network. It is usually installed within a building or a group of buildings.
2. MAN (Metropolitan Area Network): This type of network spans a small city. It is used by cable (TV) operators for program distribution.
3. WAN (Wide Area Network): This type of network spans an entire country and very often several countries. The speed of data transmission is a bit slower than that of LAN and the error rate is also high as the data has to travel over very long distances.

Computer accepts some data for its processing, that data is called input. The hardware component which allows user to enter data and instruction into a computer is called input device.

Question:Provide a list of any four services possible by the convergence of 3Cs.
A n s w e r ; Real-time navigation, Tele-medicine, Tele-geo processing application, crisis management applications and virtual laboratory.

The Ribbon is a user interface element which was introduced by Microsoft in Microsoft Office 2007. It is located below the Quick Access Toolbar and the Title Bar. It comprises seven tabs; Home, Insert, Page layout, References, Mailing, Review and View. Each tab has specific groups of related commands. It gives you quick access to the commonly used commands that you need to complete a task.

Malware is a broader term for several types of malicious codes created by cybercriminals for preying on online users. Malware is the singly coined word for the words, “Malicious Software”. Examples of malware include viruses, worms, adware, ransomware, Trojan virus, and spywares.

Types of Malware

• Computer Virus

• Spyware

• Adware

• Rootkit

• Trojan Horse

• Worm

• Ransomware

• Keylogger

• Botnet