Amplitude Shift Keying refers to transmitting data through a carrier signal by alternating the original carrier wave in reference to the encoded data. Such as:

On Off Keying (OOK) is just 100% on/off keying
Amplitude Shift Keying refers to transmitting data through a carrier signal by alternating the original carrier wave in reference to the encoded data. Such as:

On Off Keying (OOK) is just 100% on/off keying