Genus Leishmania refers to a group of parasitic protozoan species that commonly cause various diseases in humans and animals. The word "Leishmania" is already a scientific name that cannot really be replaced by synonyms. However, some terms that are associated with Leishmania are Leishmaniasis, Kala Azar, and New World Leishmaniasis. These are alternative terms used in the medical field to describe the diseases caused by Leishmania, which exhibit varying degrees of severity depending on the species of the parasite. To address and treat Leishmania infections, early diagnosis and prompt treatment are crucial. Nevertheless, research continues to explore various ways of managing the diseases caused by Leishmania efficiently.