Tengwar was a writing system used to write the angelic toungue Valarin and the Elven tongues Quenya and Telerin. Later great number of middle earth languages were written using the tengwar, including Sindarin. Tolkien used tengwar to write English. This translator takes English script and converts them to Elvish script (tengwar) using special fonts.
This translator works based on custom fonts served from the internet (@font-face). When you copy and paste unless you have the font installed locally on your system, it won't look the same.