Galaxies are vast collections of stars, gas, dust, and dark matter, and they come in several shapes and sizes. The three main types are spiral, elliptical, and irregular galaxies. Spiral galaxies, like our Milky Way, have a flat, rotating disk with arms that spiral outward, while elliptical galaxies are more rounded and smooth, lacking the distinct features of spirals. Irregular galaxies do not fit neatly into these categories and often have chaotic shapes. They can be rich in gas and dust, making them sites of active star formation. Each type of galaxy offers unique insights into the universe's structure and evolution.