COMPUTER FUNDAMENTAL (SESSION 10 AND 11)

SESSION 10: DIGITAL TECHNOLOGY AND MEDIA DEVICES

• Audio and Video Players:- MPEG Audio Layer 3 (MP3) players, CD players, and DVD players are examples of audio and video players. You can use MP3 players to play audio whereas you can use CD players and DVD players to play audio or video.
• Mobile Phones :-  A mobile phone is a wireless device that provides the capabilities of a traditional wired phone and allows you to make a call from almost any location.
• Video Game Systems:- Microsoft Xbox is an example of a video game system that is similar to a personal computer. An Xbox has a motherboard and a hard disk and supports online gaming. You play games on an Xbox by using an Xbox game disk.
• Personal Digital Assistants (PDAs) :- A PDA is a handheld computer that is used as a personal organizer. A traditional PDA includes features, such as an address book, task list, and a calculator. You can connect a PDA to a computer to transfer information.
• Digital Cameras :-  A digital camera stores images digitally on a memory device, such as a flash memory card or a mini hard disk, whereas a traditional camera stores images on film.
• Digital Video Cameras:- You can use a digital video camera to record video and store it in a digital format. Digital camcorders and webcams are examples of digital video cameras.

Analog and Digital Audio:

  Audio is of two types, analog and digital. When you speak, the sound you create is in the analog or wave format. The sound that you hear is also in analog format.

                                   Digital audio technology allows you to record, edit, and play digital audio files on a computer. Digital audio technology also lets you communicate with the computer by just speaking.

Characteristics of Digital Audio:-

1. One of the important characteristics of digital audio is that it can be compressed. 
2. Audio files are generally large. Compressed audio files save space, allow portability, and are easier to transfer over the Internet. 
3. Another important characteristic of digital audio is that it can be edited on a computer by using audio editing software.

Some Common Audio Format :-

• Wave (WAV): This format is part of a series of standards for audio and video developed for Microsoft Windows 95 as a universal sound file format.

• MPEG Audio Layer 3 (MP3): This format was developed by Motion Picture Expert Group to allow compression of audio and video for digital distribution.

• Windows Media Audio (WMA): This format was developed by Microsoft and is used to store digital audio files.

Speech synthesis:- 

                           Speech synthesis is a technology that allows the computer to speak to you by converting text to digital audio. Windows Vista has a built- in screen reader called Narrator that supports speech synthesis.

Speech recognition:- 

                               Speech recognition is a technology that allows you to communicate with a computer by using only your voice to enter text and to issue commands. To enable speech recognition, you need an audio input device, such as a microphone, a sound card, and speech recognition software that converts human speech into text or commands for the computer.
Analog Video:- 
               video was recorded, edited, and stored in the analog format on tape.
Digital Video:-
                  digital video technology allows you to record video in the digital format on a digital storage device, such as a CD, DVD, or flash memory card, and edit it on a computer by using digital video editing software.
Analog Camcorder
                   An analog camcorder records and stores video in an analog format on a tape. To edit the video on a computer, you need to convert it from the analog format to the digital format.
Digital Camcorder:-
                 A digital camcorder records and stores video in a digital format, which makes editing the recorded video easy. Another advantage is that a digital camcorder is generally lighter and smaller than an analog camcorder.Digital video editing can either be linear or nonlinear. 
Linear and Non Linear :-
                      In linear editing, you have to sequentially traverse a file to edit it. In nonlinear editing, you can directly go to the frame and remove it from your video. Tape is always in the linear format and has to be edited linearly. Random access devices, such as DVDs and CDs, let you read and write data in a nonlinear manner.

Web Video Technology:-

              These days, you can view video over the Internet. Web video technologies allow you to transfer digital video files over the Internet. Some of the examples of Web video

technologies are.

• Video Streaming

• Downloading Video

• Web Conferencing

SESSION 11: 

COMPUTER SECURITY AND PRIVACY

Computer Security: 

                       The computer hardware can be damaged due to human carelessness or natural causes. Also, the data and software on the computer need to be protected from accidental or intentional loss and tampering.

Computer Privacy:

                 Computer privacy means that your data, such as personal files and e-mail messages, is not accessible by anyone without your permission.

This table given below describes the various natural threats to computer security and privacy.

1.	Most of the components of a computer are designed to operate within a specific temperature range. In case of excessive heat or cold, some components may start to malfunction, and you may need to replace them. If your computer has been exposed to extreme temperatures, let it return to room temperature before you start it.
2.	Fire can damage your computer beyond repair. Even if the computer does not directly catch fire, the heat caused is enough to melt the delicate components inside the computer. Moreover, smoke can damage the CPU fan, which in turn can cause overheating of the CPU and damage it.
3.	Lightning that strikes with a huge amount of electrical charge can cause a surge. A surge or spike is a sudden increase in the supply voltage, which can permanently damage some components of your computer. For example, a sudden increase in voltage can destroy the motherboard of your computer.

The following table explains the measures that you can take to protect your data and computer from natural threats.

Measure	Description
Back up data	Backing up data involves creating multiple copies of your data. Events like floods and earthquakes can strike without warning. Making a backup helps you recover your data in case of any data loss.
Install computers in secure locations	Install your computer in a place where it is not likely to get damaged due to natural factors. For example, avoid installing computers in rooms that are exposed to excessive dust or moisture.
Install protective electrical devices	Install devices such as an Uninterruptible Power Supply (UPS) that can provide battery backup in case of a power outage. A UPS prevents software damage caused by abrupt shutting down of your computer.
Insulate computers from fire	Insulate the computers from fire by housing them in fire retardant surroundings. In addition, you can install adequate fire safety equipment and procedures for quick damage control.
Maintain appropriate temperature and humidity	You should maintain an optimum temperature and humidity level to ensure the smooth functioning of your computer. You can do this by installing devices such as air conditioners and humidity controllers.

Threats from Human Actions

               A type of threat to your computer is malicious human sources.

The following table describes various threats from malicious human sources and human errors to your computer.

Threat	Description
Theft	Anyone can steal your computer or its components, if they have access to it. You can also become a victim of virtual theft, when your computer is connected to the Internet. One example of virtual theft is identity theft, in which a hacker can steal your personal information to assume your identity.
Viruses, worms, and Trojan horses	Viruses are computer programs that can damage the data or software on your computer or steal the information stored on your computer. These viruses can reach your computer, without your knowledge, through the Internet or through storage devices, such as floppy disks and CD-ROMs. Worms are viruses that replicate themselves once they attack a computer, making it difficult to remove them. A common worm, known as Trojan horse is a kind of virus disguised as useful software. Once a Trojan horse reaches your computer, it starts acting like a virus causing damage to the computer’s data.
Spyware	Spyware are programs that get installed on your computer without your knowledge. They can secretly send out information about your Web browsing habits or other personal details to another computer through the network.
Internet scams	While using the Internet, you might come across some attractive offers through e-mail messages or chat room communication. You should be very careful before accepting any such offers because these offers can be part of well-planned scams that can cause you a financial loss.
Online predators	Online predators are individuals who lure anybody online, into inappropriate and unethical relationships. You or your family members can become targets of online predators. Online predators develop contact with their targets by using e-mail or chat room communication.

Accidental deletion of data	Many times, damage to a computer is due to unintentional human errors. Accidental deletion of an important file can disrupt the integrity of data or prevent other files or programs from working.
Accidental damage to hardware	Computer components, being delicate, run the risk of getting damaged due to carelessness.

The following table describes measures to protect your computer from malicious human sources and human errors.

Solution	Description
Store data safely	Keep your data in safe and secure locations that have limited access to others. This minimizes the possibility of theft or tampering of the data.
Encrypt data	The BitLocker feature of Windows Vista helps you encrypt data at the drive-level. When you encrypt data by using this feature, unauthorized users cannot access the data by removing the hard drive and attaching it to another computer.
Install antivirus and antispyware programs	Antivirus and antispyware software programs have the ability to check for viruses and spyware present in the computer’s memory and also prevent new ones from entering. Built-in features in e-mail software, such as Windows Mail, allow you to block junk e-mail messages and provide features to check for viruses and worms. Windows Vista includes Windows Defender, a built-in antispyware program, which provides real-time protection.
Install firewall	A firewall enables you to filter the Internet traffic before it reaches your computer or a private network. It provides additional protection against threats such as hackers and viruses. A firewall also helps to ensure computer privacy by restricting external access to your computer by any unauthorized user. Windows Firewall that is available with Windows Vista blocks unwanted access to your computer.
Back up data	Regularly back up important computer data. Creating multiple copies of data provides protection against loss of data due to accidental erasure or destruction of data.
Keep computer in safe environment	Keep the computer in an area that is dust-free, free from vibration, and out of the way of possible impact. Keep the computer away from any magnetic substance, water, or static discharge.

The following table explains the actions that you can take to safeguard the operating environment and data on your computer.

Guideline	Description
Implement	An effective way to minimize the risk to your operating user environment and data is to keep unauthorized individuals identification from accessing your computer.

Set username and password	You can also increase security and limit unauthorized access to your computer by setting up a username and password.
Keep password secure	Your password acts like a key to your computer. Anyone who knows your password can access your computer and tamper with data.
Lock computer	When you leave your computer on and unattended, someone can tamper with your computer software or data. You can prevent this by temporarily locking your computer while you are away.

Viruses types 

Security Measures and Techniques 

Firewall System Work