Distant galaxies are massive systems of stars, gas, dust, and dark matter that exist far beyond our own Milky Way. They are located millions or even billions of light-years away from Earth, making them difficult to observe. Astronomers study these galaxies to understand the universe's structure and evolution. Many distant galaxies are seen as they were in the past, due to the time it takes for their light to reach us. This allows scientists to learn about the early universe and the formation of galaxies. Tools like the Hubble Space Telescope help capture images of these remote cosmic structures.