Tengwar is the Elvish script Tolkien created for languages such as Quenya and Sindarin.
Tengwar means “letters” in Quenya. Tolkien designed it as a writing system whose characters could represent consonants and vowels through a structured arrangement of tehtar and other signs. Its forms appear in many fictional languages, not only Elvish ones.
The script is associated especially with Fëanor, who is said in the legendarium to have devised it. In Tolkien’s presentation, Tengwar became widely used across Middle-earth and Aman, with different modes adapting it to different languages.
Tengwar is a script, not a language. Quenya and Sindarin are separate Elvish languages, while Cirth is another writing system associated particularly with the Dwarves and later with other peoples. This distinction is one of the most common sources of confusion in discussions of Tolkien’s invented languages.