What are analog and digital modes of operation of an instrument?

In Analog communication, the analog message signal modulates some high carrier frequency inside the transmitter to produce modulated signal.this modulated signal is then transmitted with the help of a transmitting antenna to travel through the transmission channel. At the receiver, this modulated signal is received and processed to recover the original message signal. Example: AM , FM radio transmission an TV transmission. In digital communication, the message signal to be transmitted is digital in nature. This means that digital communication involves the transmission information in digital form Example: ASK, FSK, PSK.