Most times, people are so quick to use the word 'germs' when referring to microorganisms like bacteria. To understand the basic differences between the two, it is important to know their actual meaning. Germs are harmful microorganisms that cause disease.
Germs could any type of microorganisms like viruses, fungi, bacteria, etc. These microorganisms cannot be seen with human's physical eyes, but they can be seen with the aid of a microscope.
On the other hand, bacteria are just one of the examples of microorganisms that often cause diseases. The fact that some bacteria are disease-causing microorganisms does not mean that there are no good ones.
For example, some bacteria are living naturally in our bodies without causing any problem to our health. Meanwhile, germs are generally considered to be harmful microorganisms. In fact, they are also known as bad microbes, while bad bacteria, bad viruses, bad fungi, and other harmful microbes are under this classification.