it's a babylock, pacesetter with air threading.
I will finish my seams for all my projects, and serge my seams before adding binding. it leaves it nice for a binding edge.
also on fabric napkins, and other sorts like that. also on sewing cloths. but mainly just to finish the seams nciely. a rolled hem makes a nice finish on many things, like napkins or aprons. the list is endless.