The picture that graphically represents the items you use in Windows or any other OS is called an Icon. An icon is a picture that represents the program that is being used. An icon is useful for the user's to directly know what type of program they need to use or such.
The answer is 2 frequencies.
A Full-Duplex QAM 64 K Modem uses two frequencies. One frequency is used for upstream and the other for downstream. A variety of common QAM forms are available and include, 16 QAM, 32 QAM, 64 QAM, and 256 QAM. For example, for domestic broadcast use, 64 and 256 QAM are used for cable modem and digital cable TV. The modulation scheme for this modem uses both amplitude and phase.
Sorry I don't understand your question
Answer: Control
Explanation: Communication channel is the medium created for the process of the communication.These channel let the source to destination communication in a cycle so that message can be send and received respectively.
Control in the branch of communication channel is used for the handling of the communication limit of the message that is being sent and received .It puts a limitation to the extent message can be read, recorded ,movement of resource and other facilities.
