How does red shift provide evidence of an expanding universe? short and small

Redshift occurs when light from distant galaxies is stretched to longer wavelengths as they move away from us, indicating that the universe is expanding. This phenomenon is observed as a shift toward the red end of the spectrum. The greater the redshift, the faster the galaxy is receding, suggesting that the universe is not static but expanding over time. This relationship supports the Big Bang theory and helps explain the large-scale structure of the cosmos.