Parasitism

I have started to research the science of Parasites.
It is decribed as Parasitism and always found within the subject of Symbiosis when I researched it.

Symbiosis is when two organisms co-exist (where one organism benefits while the other is not affected).
Also there is Mutualism where both species benefit

A Parasite changes the Symbiosis by sometimes being predatory e.g flea on host, and one organism benefits and the other called the 'host' is harmed.

I then found a whole list of types of parasites which will be handy when i'm defining my projects.

Endoparasites - Parasites that live inside the body of the host.
Ectoparasites - Those that live on the outside of the body.
Parasitoids - are parasites that use another organism's tissue for their own nutritional benefit until the host dies from loss of needed tissues or nutrients.
Epiparasite - is a parasite that feeds on another parasite.
Biotrophic parasites - cannot survive in a dead host and so keep their hosts alive.

Interestingly there's also a term
'Social parasites' - taking advantage of social interactions.