What is a flat round or oval galaxy?

A flat round or oval galaxy, often referred to as an elliptical galaxy, is characterized by its smooth, featureless light profile and lack of distinct structures like spiral arms. These galaxies are typically composed of older stars, with minimal new star formation, and exhibit a range of shapes from nearly spherical to elongated ovals. They are classified based on their ellipticity, with more elongated galaxies appearing as "E" followed by a number indicating their flattening. Elliptical galaxies are commonly found in galaxy clusters and can vary significantly in size and mass.