technical: a group of people used in a study who have something (such as age or social class) in common. Depression was a common problem for people in that age cohort.echnical: a group of people used in a study who have something (such as age or social class) in common. Depression was a common problem for people in that age cohort.
Wi-Fi is the name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections. A common misconception is that the term Wi-Fi is short for  wireless fidelity , however this is not the case. Wi-Fi is simply a trademarked phrase that means IEEE 802.11x.
IR wireless (infrared wireless) IR wireless is the use of wireless technology in devices or systems that convey data through infrared (IR) radiation. Infrared is electromagnetic energy at a wavelength or wavelengths somewhat longer than those of red light.