GPS: Global Positioning System. The system consists of 24 Navstar satellites that orbit Earth. The satellites are monitored and controlled by stations on Earth. The satellites send back an exact location to anyone who has a GPS receiver. GPS is the most accurate navigation system developed to date. It gives latitude, longitude, altitude and time to an unlimited number of people anywhere on Earth in all kinds of weather.ADVANTAGES GPS is extremely easy to navigate as it tells you to the direction for each turns you take or you have to take to reach to your destination.

GPS works in all weather so you need not to worry of the climate as in other navigating devices.

The GPS costs you very low in comparison other navigation systems.

The most attractive feature of this system is its100% coverage on the planet.

It also helps you to search the nearby restaurants, hotels and gas stations and is very useful for a new place.

Due to its low cost, it is very easy to integrate into other technologies like cell phone.

The system is updated regularly by the US government and hence is very advance.

This is the best navigating system in water as in larger water bodies we are often misled due to lack of proper directions.

DISADVANTAGES

Sometimes the GPS may fail due to certain reasons and in that case you need to carry a backup map and directions.

If you are using GPS on a battery operated device, there may be a battery failure and you may need a external power supply which is not always possible.

Sometimes the GPS signals are not accurate due to some obstacles to the signals such as buildings, trees and sometimes by extreme atmospheric conditions such as geomagnetic storms.

HDMI : High Definition Media Interface. HDMI is just a simpler, more accurate way of transmitting data between components. HDMI is an alternative to other connections, such as DVI or component video. The system consists of digital televisions that include HDMI inputs and components (DVD players, cable/satellite boxes and Blu Ray Players) with HDMI outputs. An HDMI cable, which consists of 19 individual wires rolled into a single cable, is used to connect the two. The interface resembles a large USB connection, with 19 pins or holes.HDMI Benefits: the cable features a bandwidth of 5 gigabytes per second (Gbps) or more, providing the speed needed to transmit an HD signal, with space leftover. HDMI also transmits a pure, uncompressed digital signal. Other connections use a digital-to-analog conversion which can degrade picture quality. Unlike other video connections, HDMI also includes audio (eight individual uncompressed surround channels), thereby eliminating the need for separate audio cables. In short, HDMI can deliver the best high definition picture and highest quality sound while eliminating excess cables.Communication ProtocolsWhen two dissimilar computers systems communicate with each other they require a standard set of instructions for communicating with each other and these instructions are known as protocols. Protocols are the communications standards and the set of rules that source and destination computers must abide by and follow in order to communicate with each other. They determine that how data will be transmitted between two computer computers.

Web Communication Protocols

HyperText Transfer Protocol (HTTP)

HyperText Transfer Protocol (HTTP) is the most widely used web communications protocol. It takes this format:> "http://" at the front. HTTP is a classic "client-server" protocol. Users click a link on their web browser (the client), and the browser sends a request over the internet to a web server that houses the site the user requested. The server sends back the content of the site, such as text and images, which display in users' web browsers. HTTP is an unsecure communications protocol because the data it sends back and forth between a browser and a server is unencrypted and can be intercepted by third parties.

Telnet

Telnet client is used to access remote servers. However, unlike HTTP, where you only request specific files, Telnet is used to actually log on to the remote server and perform functions as if you were sitting in front of the server terminal. Telnet is rarely used now since it is an unsecure protocol that does not encrypt data sent between remote computers.

File Transfer Protocol (FTP)

Primarily used to transfer files such as documents, images, music, etc., between remote computers. Users have to log on to an FTP server either through a command line interface or through one of the many FTP graphical client programs available. Once logged on, users can navigate through the remote server's file structure, moving, renaming, deleting, and copying files as if it were their own computer.

Hypertext Transfer Protocol Secure (HTTPS)

HTTPS is similar to HTTP, but different in that it combines with a security protocol called SSL/TLS to provide secure client-server communications over unsecure networks such as the internet. You're most likely to see HTTPS protocols on ecommerce web sites that ask for personal financial information like credit card numbers. You know a web site is using HTTPS protocols when you see the "https://" in the web address displayed in your browser's Address field.

IP Security (IPSec)

IP Security (IPSec) protocols encrypt packets of data and send them between two computers that share the same cryptographic keys. IPSec protocols are used in Virtual Private Networks.

VPN Type of Network that allows employees of a company to log on to their company's secure network through a public network (e.g. from home or a coffee shop.)

Email Protocol

Email protocols are the languages and rules that email servers and clients use to communicate with each other and manage incoming and outgoing mail. These protocols are strictly defined and are in use in a variety of different email clients. In addition, each email protocol has a unique way of managing email that is sent and received from an email account.

Post Office Protocol

Post Office Protocol (POP) is an email protocol that has been in existence longer than many other protocols. POP uses the email server as a temporary waiting place and then forwards all of your emails to your computer and removes them from the server.

Internet Message Access Protocol

Internet Message Access Protocol (IMAP) is a popular alternative to POP. IMAP works by keeping your email on the email server. One benefit of IMAP is that you can access your email from multiple computers, such as a home and work computer and a mobile device

Simple Mail Transfer Protocol

Simple Mail Transfer Protocol (SMTP) is a specialized email protocol. Both POP and IMAP use SMTP to manage outgoing (sent) email.

Messaging Application Programming Interface

Messaging Application Programming Interface (MAPI) is a proprietary mail protocol developed by Microsoft. MAPI is specifically developed to support the Microsoft Outlook email client and the Microsoft Exchange server.

Different Types of Email Client Exploits Malware Distribution: Hackers with malicious intent can exploit your email client by distributing malware through email messages. The malware includes viruses, worms, rootkits, Trojans, keyloggers, spyware, and adware, to name a few types. The malware is distributed via an email attachment or sometimes by simply opening an email message. More often than not, the mail message is disguised as a message from someone you know when in reality; it is sent by the hacker.

Phishing Attack: A phishing attack is generally not hazardous to the inner workings of your PC however; it is designed to trick you into revealing your personal information, passwords, or bank account information. For example, if you use PayPal, the phisher sends you a message that looks like it came from PayPal. The message requests you to verify your account information with PayPal to continue using your account. The message proceeds to tell you that if you do not verify the information your account will be closed. Someone that is unaware of phishing scams easily gets tricked into revealing their account information. These types of messages are set up to look like the real deal.

Spam Attack: Spam is unsolicited email or "junk" mail that you receive in your Inbox. Spam generally contains advertisements but it can also contain malicious files. When you click on spam, the files are downloaded into your email client and into your PC. The same thing can happen if you reply to spam in an attempt to get removed from the list.

Denial of Service Attack: A denial of service attack occurs when the hacker sends multitudes of email messages to your email client in an effort to block you from using your email client or crashing your computer altogether. In the case of an organization, a denial of service attack on email can crash an entire network and prevent the users from responding to legitimate traffic.

Malware, short for malicious software, is software used or programmed by attackers to disrupt computer operation, gather sensitive information, or gain access to private computer systems.Malware includes

*computer viruses,

*ransomware,

*worms,

* trojan horses,

*rootkits,

* keyloggers,

*dialers,

*spyware,

*adware,

*malicious BHOs,

*rogue security software the majority of active malware threats are usually worms or trojans rather than viruses. In law, malware is sometimes known as a computer contaminant, as in the legal codes of several U.S. states.bugs HYPERLINK "http://en.wikipedia.org/wiki/Malware" \l "cite_note-5"

Malware is different from defective software, which is a legitimate software but contains harmful that were not corrected before release.

How to help protect your computer from malware

There are several free ways to help protect your computer against malware:

Make sure automatic updating is turned on to get all the latest security updates.

Keep your firewall turned on.

Don't open spam email messages or click links on suspicious websites.

Download Microsoft Security Essentials, which is free, or another reputable antivirus and anti-malware program. If you run Windows 8 or Windows RT, you dont need Microsoft Security Essentials. (see the warning below).

Scan your computer with the Microsoft Safety Scanner.

Email client

Also called email reader, or more formally mail user agent (MUA), is a computer program used to access and manage a user's email.

The term can refer to any system capable of accessing the user's email mailbox, regardless of it being a mail user agent, a relaying server, or a human typing on a terminal. In addition, a web application that provides message management, composition, and reception functions is sometimes also considered an email client, but more commonly referred to as webmail.

Examples OF Email Clients

Microsoft Outlook, IBM Lotus Notes, Pegasus Mail, Mozilla's Thunderbird, KMail in the Kontact suite, Evolution and Apple Inc.'s Mail.5