Short answers, pulled from the story.
The term ethnology (ethnologia in Latin) was coined by Adam Franz Kollár (1718-1783) and first published in his work Historiae ivrisqve pvblici Regni Vngariae amoenitates, issued in Vienna in 1783. He defined it as the science of nations and peoples that inquires into their origins, languages, customs, and institutions.
Ethnography is the close study of a single cultural group through direct contact, while ethnology compares and analyzes the research gathered by multiple ethnographers across different cultures. Ethnology is the comparative discipline; ethnography is the fieldwork that supplies its raw material.
Claude Lévi-Strauss developed structural anthropology, a method aimed at discovering universal invariants in human society. He argued that the incest taboo was the one rule present in every known culture and was a leading figure in the French school of ethnology, which became particularly significant from the early 1950s onward.
The fifteenth-century European exploration of the Americas forced new thinking about cultural difference and generated concepts like the "Other" and the "noble savage." These frameworks, which placed civilization against barbarity in a dualist way, became central targets for later ethnological criticism and shaped debates about ethnocentrism that continue today.
Since the nineteenth century, thinkers including Hegel, Marx, Nietzsche, Foucault, Derrida, Althusser, and Deleuze have criticized claims about a fixed human nature. Lévi-Strauss and structuralism sought universal cultural invariants, but these claims have faced sustained philosophical challenge across both the nineteenth and twentieth centuries.
Ethnology developed along independent paths in different parts of the world. Cultural anthropology became dominant especially in the United States, while social anthropology took hold in Great Britain. The distinction between ethnology, cultural anthropology, and social anthropology is considered increasingly blurry.