Question

Explain the relationship between an infectious disease and a contagious disease.

Answer 1

Infectious diseases are caused by microscopic germs (such as bacteria or viruses) that get into the body and cause problems. Some — but not all — infectious diseasesspread directly from one person to another. ... Contagious diseases (such as the flu, colds, or strep throat) spread from person to person in several ways.

Answer 2

Infectious diseases are usually caused by bacteria, viruses, fungi, or parasties and transmitted through microorganisms in the air or water.

 And contagious diseases are transmittable by contact from one person to another and/or  if a person touches an infected area.