The script J.R.R. Tolkien designed for many Elvish languages is Tengwar.
Tengwar is a writing system created by Tolkien for the languages of Middle-earth. In the fictional history, the Elf Fëanor devised it, and it was later adapted for different languages, including Quenya and Sindarin. The letters are called tengwa, while tengwar is the plural form.
Tolkien developed the script as part of his broader approach to constructed languages. Its letter shapes and spelling conventions vary according to the language being written, so Tengwar is not simply a single alphabet with one universal pronunciation. It can represent vowels using tehtar, marks placed above or below consonant letters, in some modes.
Cirth is a different Tolkien script, associated especially with inscriptions and the Dwarves. Sarati is an earlier writing system in Tolkien’s invented history. These names are often confused because Tolkien created several scripts, but Tengwar is the best-known system used for Elvish writing.