Arabic calligraphy is quite fascinating because there are many styles of written Arabic. The script that's fairly similar to the script usually used in books is called Naskh.
^^^ Three variants of the Naskh style. Each line says bismillah, ar-rahman, ar-raheem.('in the name of God, The Most Gracious, The Most Merciful').
Kufi script stands out as very square, with points and straight lines.
^^^ Kufi style, saying the same as the Naskh lines.
Thuluth is similar to Naskh, but more elaborate.
^^^ Thuluth style.
Tughra has its own kinda character, and can be written into various shapes.
^^^ Tughra style.