Fungi are eukaryotes with many functions. Earlier, fungi were classified in the plant kingdom but were later classified as a separate kingdom due to their unique cell walls. Fungi are heterotrophs like animals and are more closely related to animals. The perception of fungi is inconspicuous due to their small sizes and their ability to grow symbiotically in plants, animals, other fungi, and parasites. Fungi are used for their nutrition, fermentation potential, and bactericidal potential. However, fungi are also toxic due to certain bioactive compounds known as mycotoxins. Candida and Aspergillus are invasive species that contribute to a high percentage of mycoses in oncological and haematological patients. The mortality rate due to invasive aspergillosis and candidiasis is high, at 4% and 2%, respectively. In the agriculture sector, a significant contributor to damage to crops globally is the invasion of filamentous fungi. Fungi invasion destroys over 125 million tons of wheat, rice, soybeans, potatoes, and maize annually. If prevented, 600 million people may be fed. Therefore, it is vital to consider the dual role of fungi, therapeutic, and pathogenic.