What difference between disease and disorder?

Not much: Usually used interchangeably, but disease tends to be temporary and disorder tends to be long-standing condition.

Very similar terms: and often used interchangeably, however more often disease involves a pathogen, like bacterial or viral infection, or structural abnormality or dysfunction such as in heart disease, inflammatory bowel disease, kidney disease, etc A disorder more often connotes disruption/disturbance of normal physiologic, physical or mental function which may be acquired or present from birth(mood or genetic d/o)