Lyman break galaxies are distant, star-forming galaxies that are identified by a break in their spectral energy distribution at wavelengths shorter than the Lyman limit of 912 Å. These galaxies are typically high-redshift galaxies, meaning they are located very far away in the universe and thus observed as they were billions of years ago. Lyman break galaxies are important for studying the early universe and galaxy formation, as they provide insights into the processes of star formation and evolution in the early universe. Researchers study Lyman break galaxies using a variety of observational techniques, such as spectroscopy and multi-wavelength imaging, to understand their properties and evolution over cosmic time.