J.R.R. Tolkien developed Quenya as a fictional language influenced strongly by Finnish. In his mythology, Quenya is an ancient language of the Elves, especially associated with the Ñoldor and the high-elven tradition.
Tolkien was a professional philologist, so Quenya was designed with systematic sounds, grammar, vocabulary, and historical development rather than as a random collection of invented words. Finnish influenced its sound and structure, while Latin and Greek also contributed to aspects of its design.
Quenya is sometimes called “High-elven” or “Elvish” in general discussions, but those labels can cause confusion. Tolkien created many languages, including Sindarin, which became the most widely spoken Elven language in much of Middle-earth during the Third Age.
The language appears in names, poems, formal speech, and inscriptions. Its use helps distinguish cultural settings and historical periods. Tolkien continued refining his languages throughout his life, so some forms vary across drafts and publications.