If a star is moving away from an observer, the observed shift in the wavelength of its light is called?

If a star is moving away from an observer, the observed shift in the wavelength of its light is called?

اگر کوئی ستارہ کسی مبصر سے دور ہو رہا ہو تو اس کی روشنی کی طول موج میں مشاہدہ شدہ تبدیلی کہلاتی ہے؟
Explanation

When a star is moving away from an observer, the wavelength of the light it emits appears to be stretched or shifted toward the red end of the spectrum. This phenomenon is known as redshift.