A simple Wi-Fi guide
Wi-Fi, the short form of "Wireless Fidelity", is the technology that allow our Internet-connected devices to become a part of a network, be it local or public, without using wires. It utilizes wireless signals, radio waves which are encoded (using one of the Wi-Fi Alliance protocols) at one end, and are decoded at the other end. It's a two-way communication process, so all the devices that utilize Wi-Fi need to incorporate both data transmitters and receivers.
According to a recent Data Alliance survey, over 85% of US citizens utilize wireless networks to connect their devices to the Internet. Unlike TV stations, though, wireless networks utilize low-power transmitters/radio signals, and this limits their range and performance.
If your devices can connect to the Internet wirelessly, this happens because there's a device called "router" in your home. The Internet signal cable, which was installed by your ISP (Internet Service Provider), is connected to the WLAN plug that is usually placed on the back side of the router. Once that the device is powered on, it starts to emit radio waves that can be received by your smartphone, tablet, laptop or desktop computer.
A router is, in fact, a special type of modem; it is a low-power computer that can handle connections to various Internet websites and services. Often, a router will also provide wired (LAN, Local Area Network) connections, which offer better performance, but may not be that convenient, especially when you need to utilize lots of portable devices.
The typical range of a router is 50...300 feet; routers that incorporate more antennas are more efficient, of course, because they can adjust signal broadcast power intelligently. You can look up MIMO on the Internet to discover how these intelligent antennas work; here's a pdf report which presents the basics.
It goes without saying that your devices should also incorporate a wireless card or a dedicated Wi-Fi module; otherwise your router will be useless! While all smartphones and most tablets already provide Wi-Fi connectivity, older laptops and computers may miss a wireless card. Fortunately, you can purchase standalone Wi-Fi adapters that can either be installed on the motherboard of your PC, or plugged into an available USB connector. Older laptops, which may not have an available USB connector, can also utilize a PCMCIA card to get access to wireless Internet.
Since they have enough CPU power and already incorporate the needed hardware and software, most of your Internet-ready devices (also known as network clients) can be turned into virtual routers. It's the perfect scenario when you are away from your Wi-Fi network, and still want to have Internet access on your laptop by turning your smart phone, which has Internet access, into a special router, called "hotspot". Both iPhones and Android phones offer easy ways of doing this. It's not the perfect solution, of course, because mobile data can cost quite a bit, but it's the safer way of doing things when you are traveling, for example.
Wi-Fi technologies are constantly updated, offering higher speeds and increased security. It's a necessity, because public hotspots, which are available in airports, college campuses, libraries, etc. can pose serious security risks. A hacker could sit right next to you in a coffee bar, for example, and if your phone is connected to that open hotspot, he will be able to log into your device, and then steal or delete your data.
Therefore, the best way of protecting your device is to stay away from public hotspots. And when you are at home, ensure that your Wi-Fi network is encrypted using the most recent security standard (WPA2, at the moment) and utilizes a long, hard to guess password. Of course, if you only use a desktop computer, don't enable the wireless component of your router. Instead, connect your PC to the router using an Ethernet cable, and you will benefit from increased security and higher Internet data transfer speeds.