Microscopic fungi are tiny organisms that can only be seen with a microscope. They play essential roles in nature, breaking down organic matter and recycling nutrients in ecosystems. Common types include yeasts and molds, which can be found in soil, on plants, and even in the air. These fungi reproduce through spores, which can spread easily and grow into new fungi under the right conditions. Some microscopic fungi are beneficial, such as those used in bread and beer production, while others can cause diseases in plants and animals. Understanding these organisms is crucial for agriculture and medicine.