Mirrorless cameras have become very popular in recent years. 2019 was the year of the mirrorless, with an incredible amount of mirrorless cameras released and very few new DSLR models. A mirror less camera is in fact a DSLR without a mirror.
This makes it a combination of compact and DSLR while maintaining the small size of a compact and the excellent quality of a high-end camera. The clear advantage is small size, interchangeable lenses and large sensor (good low light performance and superb image quality). The disadvantage is no viewfinder and sometimes less choice of lenses.