Only DSLR's have a viewfinder.

Many camera types besides DSLRs have viewfinders. Mirrorless cameras often feature electronic viewfinders (EVFs), rangefinder cameras have optical viewfinders, and even some compact cameras include small optical or electronic viewfinders. The viewfinder is not exclusive to DSLRs - it's a framing aid found across various camera formats. What differs is the viewfinder type (optical vs. electronic) and how it receives the image.