Doppler's effect is the effect on how waves behave when they are moving towards an object, or moving away from an object.
In daily life
When you hear an ambulence moving towards you from behind, it has a high pitch, but when it is moving away, it lass low pitch.
Why does this happen?
: It's because when the ambulence is moving towards you the sound waves get compressed, and what happens is many sound waves entered your ears at the same time, so the pitch is high. When the ambulence moves away, you will hear low pitch, because the waves are getting expanded, and you only get a few sound waves entering your ears in a sec.
<== Watch this video, for visual understanding.
What is a pitch?
About:(A few things you need to know)
Red shift And Blue shift
I have a question.
Red shift is increase in wavelength, that means the wave whould be moving away from an object right? So for another, opposite object, the light must be moving towards it and so would it be blue shift? So is it all relative?