Host :
- It can be defined as the organism which harbors and provides support for another organism.
- A host is larger than the organism which harbors it.
Primary host :
- A primary host is defined as the host that a parasite or any other organism requires to become sexually mature to reproduce and spread infection.
- It can be a human or any other living organism.
Example: The primary host of the malarial parasite Plasmodium is the female Anopheles.