raw is untreated denim. not distressed or anything that would alter its state when being made.
selvage is a type of loom that was made from vintage machines from the 80s where the edge of the loom is seen. back in the day, before they invented more efficient ways to make denim, everything was selvage (or selvedge). this process was more tedious to produce and the tension of the threads are supposed to be more uneven giving the jeans a more "natural" look when worn out.
when more efficient machines were invented, the japanese cornered most of the machines that make selvage denim and continued to make jeans the old fashion way. they also played around with the dyeing process and the slubbiness of the material.
here is my oni denim w/c are supposed to be one of the most slubby denim made:
here are pics of 2 oni denims. one is worn for about 1.5years (washed for the first time after 6 months) and the other is brand new: