Oomycetes, commonly known as water molds, are a group of fungus-like organisms found in aquatic and terrestrial environments. They are classified in the kingdom Stramenopila and are characterized by their filamentous structure and the production of motile spores with flagella. Oomycetes play important roles in ecosystems, often decomposing organic matter and recycling nutrients. Some species of oomycetes are known to be pathogens, causing diseases in plants and animals. A well-known example is Phytophthora infestans, which is responsible for the potato blight that led to the Irish Potato Famine. Understanding oomycetes is crucial for agriculture and environmental management.