Trematodes, commonly known as flukes, are a type of parasitic worm belonging to the class Trematoda. They typically have flat, leaf-like bodies and can live in various hosts, including humans, animals, and fish. These worms often inhabit the liver, lungs, or intestines of their hosts, where they can cause various health issues. These parasites have complex life cycles that usually involve multiple hosts, including snails as intermediate hosts. Trematodes can lead to diseases such as schistosomiasis, which affects millions of people worldwide. Understanding their biology and life cycle is crucial for developing effective treatments and prevention strategies.