Differential geometry (DiffGeo) merges calculus and geometry, enhancing both fields with advanced mathematical frameworks. A solid foundation in calculus and differential equations is essential, along with familiarity in abstract algebra and general topology for deeper understanding. Many online resources focus on the physics applications of DiffGeo, particularly in areas like general relativity and quantum mechanics, but less on its pure mathematical aspects. Notably, while physics courses often do not require DiffGeo as a prerequisite, they typically cover necessary concepts within the curriculum. For those interested in tutorials, various links to resources and lecture notes are available, including those from reputable institutions.