What is meant by Koch's postulates?

Answer: four criteria to establish a causative relationship between a microbe and a diseases

Explanation:

1 - "Bacteria must be present in every case of diseases"

2 - "Bacteria must be isolated from the host with the diseases and grown in pure culture"

3 - "The specific diseases must be reproduced when a pure culture of bacteria is inoculated into a healthy susceptible host"

4-"Bacteria must be recovered from the experimentally infected host"