what do you mean by obligate parasites?

Obligate parasites are organisms that are completely dependent on a host for their survival and reproduction. Unlike facultative parasites, which can live independently or with a host, obligate parasites must live in or on a host organism to complete their life cycle. They cannot survive or reproduce without a host.

These parasites often cause harm to the host as they draw nutrients from it or damage its tissues. Examples of obligate parasites include certain types of bacteria, viruses, and some fungi. For instance, Plasmodium, the parasite that causes malaria, is an obligate parasite because it requires a host (such as a human or mosquito) to complete its life cycle.