First contact is a term describing the first meeting of two cultures previously unaware of one another. One notable example of first contact is that between the Spanish and the Arawak (and ultimately all of the Americas) in 1492.
Such contact is sometimes described later by one or both groups as a "discovery", particularly by the more technologically developed society. In addition it is generally the more technologically complex society that is able to travel to a new geographic region to discover and make contact with the generally more isolated, less technologically developed society, leading to this frame of reference. However, some object to the application of such a word to human beings, which is why "first contact" is generally preferred. The use of the term "discovery" tends to occur more in reference to geography than cultures; for an example of a common discovery debate, see Discoverer of the Americas.
The historical record indicates that when one culture is significantly more technologically advanced than the other, this side will be favored by the disruptive nature of conflict, often with dire consequences for the other society. The introduction of disease can also play a role and has worked to the advantages of both lesser technologically advanced and more technologically advanced societies, e.g. negatively for indigenous American civilizations and positively for Africans and some others[1].
Fiction about the topic is commonplace in science fiction and fantasy. In science fiction, the first contact trope explores the possibilities of first contact between two intelligent species, generally humans and extraterrestrials.
See, for example, Jared Diamond's Guns, Germs, and Steel. The indigenous Americans, particularly in the Caribbean (and island peoples in general) lived in relative biological isolation compared to Europeans who were exposed to pathogens that spread across Eurasian trade routes. Africa had a similar but different internal interplay and was also exposed from the northeast to pathogens from Eurasia which worked until the late nineteenth century.