In Arabic Writings there are so many of them. But with the passage of time, two became most popular. These two most popular Arabic writings are thus as follows:
Khat al-Kufi (the Kufic styles or Geometric scripts)
The Kufic style of writing is compared to other cleaner and more geometric. It has a kind of visible rhythm and stress on horizontal lines. At the developing stages, the vowels were noted as red dots; consonants later became distinguished with small dashes top or down of the letter to make the texts more readable. A number of Arabic Art of the past and Qur'an written in this style have been found in different places in history, like the Mosque at Kairouan, in Tunisia and some ancient coins.
This style was very common in the Andalus and Maghrib, thus they had the most common scripts of it. It is noted too that the Maghrib script and its Andalus variant are less rigid versions of Kufic, with more curves. Although, this style of writing has been generally replaced by the second script, yet it remains very useful hitherto in decoration and designs.
Khat an-Naskh (the Cursive style)
The Naskh styles of writing (or calligraphy) appeared later than the first style, the Kufi style. It was much easier to write and read. It thus replaced the earlier Kufi style, except for decorative purposes. It became the hand writing made use of in writing the Qur'an and other documents.
The standard scripts of this style are six in number. They were pioneered by Ibn Muqla Shirazi and were later fine tuned by his successors Ibnul Bawwab and Yaqut al-Mustasimi. The six scripts are: Naskhi, Riqaa', thuluth, tawqi', muhaqqaq and rayhani.These are the basic six scripts of the cursive style.
After some time in the history some others started emanating from different parts of the ummah. Some of them are: Nasta'liq, bihari, shikasteh and diwani. In China there is a deviced writing called "sini", which mean Chinese. It is very evident on this style influences from the Chinese writings. A horsehair brush instead of the standard reed pen is used.
These are the most famous and common Arabic calligraphic writings through the history. The naskh and ruqa' remain the most widely used till date. However, ruqa' is very common amidst upper class modern Arabic writers while naskh is generally used in teaching children, who are later introduced to ruqa'.