Valarin is the language J.R.R. Tolkien created as the language of the Valar in his mythology.
The Valar are powerful spirits who enter and shape the world of Arda. Their native speech is Valarin, though the language is only sparsely represented in Tolkien's writings. The Eldar encountered it in Valinor and adapted some Valarin names and words into their own languages.
Quenya and Sindarin are more extensively developed Elvish languages. Quenya is associated especially with the High Elves and has a formal, classical role, while Sindarin became the everyday Elvish language of much of Middle-earth. Adûnaic is the language of Númenor.
Because Tolkien invented many related languages and often presented linguistic history across different eras, readers can easily confuse their roles. Valarin is the specific answer for the speech of the Valar, not the best-known Elvish tongues.