Fungi are found everywhere on Earth and play critical roles in breaking down organic matter, supporting plant growth, and providing food and medicines. Scientists have recently reorganized how fungi are classified into nine major groups using genetic analysis, which has helped clarify evolutionary relationships that were previously unclear. This comprehensive review explains what distinguishes each fungal group, how they are related to each other evolutionarily, and why fungi deserve more attention in biology education given their importance to human life and global ecosystems.