Arabic lettering refers to the Arabic script, which codifies the written Arabic language. Arabic numerals refer to two written numbering systems: Western Arabic numerals, such as 0, 1 and 2, as used in most written languages of European descent, and Eastern Arabic numerals, as used in the written Arabic language.
The Arabic alphabet consists of 28 letters and is written from right to left in a cursive style. The alphabet primarily consists of consonants. When the language is written the reader must fill in the vowels. The Arabic script has been adapted for writing other languages, including Persian, Malay and Pashto.
Western Arabic numerals have been used in written European languages since at least the 10th century, although Roman numerals remained the dominate numbering system until the 14th century. Western Arabic numerals, which originated in India, reached Europe via Persia and were not historically used in conjunction with the Arabic alphabet. However, some countries that use the Arabic script, such as Morocco and Tunisia, use Western Arabic numerals.
Eastern Arabic numerals, which originated with the Arabic alphabet, bear little resemblance to Western Arabic numerals, other than the number 9. Unlike Arabic lettering, Eastern Arabic numerals are written from left to right.