Definition of Spores:

A spore is a reproductive cell produced by plants (fungi, moss, ferns) and some protozoa and bacteria. The spore often fully develops after a state of dormancy or hibernation.

Certain bacteria produce spores as a defensive mechanism. Bacterial spores have thick walls and are very resistant to high temperatures, humidity, and other unfavorable conditions.

Information:

Chemical disinfection kills bacteria, but does not destroy their spores. Sterilization destroys spores as well as bacteria, and requires high temperatures and high pressures. In health-care settings, sterilization is usually accomplished using a device called an autoclave.