Lama and geshe name two related but distinct kinds of standing within Tibetan Buddhist monastic education, and the two are sometimes confused by outside observers. Geshe is a formal academic degree, roughly comparable to a doctorate, awarded after an extended course of monastic study, commonly spanning fifteen years or more in the major Gelug monastic universities, that culminates in public examination and debate on Buddhist philosophy, logic, and the classic commentarial literature; it certifies a specific, rigorously assessed level of scholastic achievement.
Lama, by contrast, is a broader title for a qualified teacher and does not depend on completing any single defined curriculum or passing any centralized examination, so a person can be addressed as lama on the strength of a teacher's personal authorization and recognized ability to guide students, whether or not he has also earned a geshe degree. A geshe who goes on to teach is commonly also addressed as lama, since the scholarly degree does not by itself confer teaching authorization the way a teacher's personal transmission does, while many respected lamas, particularly in non Gelug schools that place less institutional weight on the geshe system, teach without ever having pursued that specific academic credential at all.