Question

what is wave????????????

Answer 1

In physics, a wave is an oscillation accompanied by a transfer of energy. Frequency refers to the addition of time.
A wave can be described as a disturbance that travels
through a medium from one location to another location. 
One way to categorize waves is on the basis of the direction of movement of the distinct particles of the medium relative to the direction that the waves travel. Waves can be classified into two types Longitudinal Wave and Transverse Wave. 
hope this helps you....:)

Answer 2

In physics, a wave is an oscillation accompanied by a transfer of energy. Frequency refers to the addition of time.
source:-Wikipedia