High-redshift galaxies refer to galaxies that are located very far away from Earth, at distances where their light has been redshifted to longer wavelengths due to the expansion of the universe. These galaxies are typically found at redshifts above z~1, meaning they are billions of light-years away from us. Studying high-redshift galaxies provides important insights into the early universe and the processes of galaxy formation and evolution. Researchers use telescopes and observatories to observe these distant galaxies, analyzing their properties such as their morphology, star formation rates, and chemical composition. By studying high-redshift galaxies, scientists can better understand how galaxies have evolved over cosmic time and the factors that have influenced their development.