What is a modem?

MoDem(Modulator And Demodulator)
The most common type of Modem in a regular household is either a dsl,cable, or dialup modem, and they are all used to connect with the internet..

The length of a digital signal is very limited based on it's high speed and nature. 

when longer connection distances are needed, special analog types of communication are needed which can reliably transfer the signal to the end point (ISP, phone switching station, Cable Distribution network, etc).

How to boost up your Wi-Fi Strength

 Wi-Fi means Wireless Fidelity. It allows device such as a personal computer, video game console, cellphone or digital audio player to connect to the Internet as long as they are within the range of a wireless network’s broadcast range. Nowadays, there are already several ways to maximize your Wi-Fi range so that you can be more comfortable without spending too much. There are already homemade alternatives that you can do easily. I will state some of them below:

What Is WiFi®?

Wi-Fi®, is a wireless networking technology used across the globe. Wi-Fi® refers to any system that uses the 802.11 standard, which was developed by the Institute of Electrical and Electronics Engineers (IEEE) and released in 1997. The term Wi-Fi, which is alternatively spelled WiFi, Wi-fi, Wifi, or wifi, was pushed by the Wi-Fi Alliance, a trade group that pioneered commercialization of the technology.

In a Wi-Fi® network, computers with WiFi® network cards connect wirelessly to a wireless router. The router is connected to the Internet by means of a modem, typically a cable or DSL modem. Any user within 200 feet or so (about 61 meters) of the access point can then connect to the Internet, though for good transfer rates, distances of 100 feet (30.5 meters) or less are more common. Retailers also sell wireless signal boosters that extend the range of a wireless network.

WiFi® networks can either be "open", such that anyone can use them, or "closed", in which case a password is needed. An area blanketed in wireless access is often called a wireless hotspot. There are efforts underway to turn entire cities, such as San Francisco, Portland, and Philadelphia, into big wireless hotspots. Many of these plans will offer free, ad-supported service or ad-free service for a small fee. San Francisco recently chose Google to supply it with a wireless network.