1. Airborne Transmission: Pathogens travel through the air in droplets or particles, usually from coughing, sneezing, or talking. Examples include influenza, tuberculosis, and measles.

2. Contact Transmission: This can be direct (person-to-person) or indirect (through contaminated objects).

* Direct Contact: Touching an infected person, shaking hands, kissing, or sexual contact. Examples include colds, flu, and some sexually transmitted infections.

* Indirect Contact: Touching a contaminated surface like a doorknob, keyboard, or shared utensils. Examples include norovirus, common colds, and staph infections.

3. Foodborne Transmission: Pathogens enter the body through contaminated food or water. Examples include salmonella, E. coli, and norovirus.

4. Vector Transmission: An organism (insect or animal) carries the pathogen and transmits it to a human. Examples include mosquitoes transmitting malaria, ticks transmitting Lyme disease, and fleas transmitting plague.