Questions

The path that data takes from source to destination is called a Channel. A channel is a communication medium. A channel has a certain capacity for transmitting information. 

The "capacity" of a channel is the theoretical upper-limit to the bit rate over a given channel that will result in negligible errors. Channel capacity is often measured by its Bandwidth in Hz or its data rate in bits per second.

RADAR stands for Radio Detection and Ranging.

Radar is a detecting system that uses radio waves to determine the range, angle, or velocity of objects. It operates in the ultra-high-frequency of the radio-frequency (RF) spectrum.

Uses ::

To detect

aircraft,

ships,

spacecraft,

guided missiles,

motor vehicles,

weather formations, and

terrain.

It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

ITIL (Information Technology Infrastructure Library) is owned by Axelos since, 2013.