What is Wi-Fi ?
Wireless Fidelity, commonly known as Wi-Fi, is a set of networking technology that using radio wave as a media for transmitting data. Wi-Fi comes from WFA (Wi-Fi Alliance), a global non profit group of companies with their primary goal is to promote wireless networking technology based on 802.11 technology.
A networking product that has been tested is labeled with Wi-Fi Certified Logo.

In earlier times, the term Wi-Fi was only use with the device that meets the 802.11b standard which operates in 2.4 GHz frequency. It became rapidly famous with many access points service across the United States.
Then, these standards is spreading around the world, allowing users with wifi capable device such as laptops, PDA’s, Cellulars to connect anywhere that provides Wi-Fi access point.

There are three standards which represents the connection speed.
802.11a works in 5 GHz frequency with 54 Mbps maximum data rate, 802.11b works in 2.4 GHz frequency with 11 Mbps maximum data rate and 802.11g works in 2.4 GHz frequency with 54 Mbps maximum data rate.
All of these Wi-Fi standards are fast enough for a broadband connection.

These days, Wi-Fi has become one of the most important thing that support the growth of industry.
Many electronic vendors have equipt their new products with Wi-Fi. Lots of office workers using Wi-Fi to support their work such as transferring data, sending and receiving emails, online conference and many more.

No Strings Attach is probably what most people will say about this technology.

How secure is Wi-Fi ? I believe this question will come across in your mind.
Well, Wi-Fi continues to have security issues. WEP (Wired Equivalent Privacy) is used in the physical data link layer. It will secure the data transmitted from one point to another point.
Even though it is protected with WEP technology, it still vulnerable because it uses radio waves as transporting media and become easier to capture. Especially for the equipment that uses shared keys for a long time. As it can get into other hands that trying to use it with a wrong motive. So, it is necessary to change the key periodically.

source :
www.wi-fi.org
en.wikipedia.org/wiki/Wi-Fi_Alliance
en.wikipedia.org/wiki/Wi-Fi