Font and Typographical Considerations

Typography of body text is the first thing an author should care about.

Arabic Style and Calligraphy

Arabic styling and writing has its origin in Islamic art and civilization, essentially used to decorate mosques and palaces, as well as in beauty manuscripts, books, and especially to copy the Koran. Arabic script is cursive  making it viable to support  different geometric shapes overlapping and composition. Words can be written in a very condensed form as well as stretched into elongated shapes, so that scribes and artists of Islam labored  with passion to take advantage of all these possibilities.

From the beginning of Arabic calligraphy, two tendencies or two types of styles can be seen emerging, the handwriting for the decoration of mosques and sculptures, complex and shaped enough, and writing style reserved for writing the Koran, easier to use and more readable.

Writings styles / Arabic Scripts then evolved according to cultural diversity, leading to regional calligraphic schools and styles (Kufi in Iraq, Farissi and Taʻliq in Persia or Diwani in Turkey), or to the purpose of writing, such as the copying and dissemination of the Korʼan.

In general we group under the generic term  Naskh (copy/inscription) the scripts   which are meant for reading at smaller sizes and reserved suitable for books and texts to be read, e.g. the Korʼan, and as Kufi (from city of Kufa in Irak) the stylish scripts ornaments oriented. Although further named styles appeared during the richer evolution of  Arabic scripts.

Different Types  of Writing Style

Basics and principles of Arabic writing were then defined by Ibn Moqlah (886-940 Higra) @@add a ref. Welch 1979@@  who defined the Six Styles of writing: Kufi, Thuluth, Naskh, Riqaʻ, Diwani and Taʻliq.

Kufi
One of the oldest and well known Arabic scripts. It is characterized by  its decorative and prononced geometric forms well adapted for architectural design. The style grew up in the beginning of Islam for the need for Muslims to codify the Koran. @@ The script has some variations as Al MouthafarAl Mukhamal, Al Handassi...)@@
Thuluth
(The third) One of the finest Arabic scripts by its beauty and sight. Recognizable by the fact that the letters and words are very interleaved in it complex form. May be the most difficult in writing (need more skill), both in terms of letters or in terms of structure and composition.
Naskh
One of the clearest scripts at all, with clearly distinguished letters which facilitates the reading and the  pronunciation. Can be written with small size (traditionally pens made of reeds and ink) which suits with writing longer texts written in boards and books intended for general population, especially the Koran. Currently Naskh is considered the standard script for almost all the Arabic and Muslim world.
Riqaʻ
The so-called in relation to a patcher, which is gazelle's leather. Designed to be used for education, daily (not artistic) writing and adopted in the Offices (Deewan) of the Ottoman Empire.
Taʻliq
aka Farisi(Iran), Taʻliq (hanging) combines Naskh and Riqaʻ (and Thuluth?). Beautiful script  characterized by the precision and stretch of its letters, its clarity and and lack of complexity. Considered as one of the best scripts in the world and is favored by many Arabs calligraphers.
Deewani
TBD 
Nastaaliq Farissi
TBD as Persian version derived from Nas(kh) and Taaʻliq. It is like a Taaʻliq but easier to write and read...

Fonts and Styles

Until recent years, Arabic typefaces were not as common and various as the Western ones. Although Arabic was subjected of Western printing techniques, the number of different letters, absence of upper/lower cases, contextual shapes, the joining of the letters result in simplified typefaces.

The reasons might be both technical and historical / Cultural.

Is this because Arabic world, like other parts in the world, came to the computer world more lately than the Western world?

According to Bil'Ak,  "Not enough designers from Arabic word  have paid attention to creating Arabic fonts or have been slow to address challenges presented by adapting Arabic script to screens", "May be because there are few specialized typography courses available in the Middle East."

Other possible reason, is that not all typographic concepts apply all to the Arabic script (e.g. serif, case...) and that other characteristics  should be handled carefully for better readbility (@@to provide example@@).

Now, many  tools are available to design Arabic fonts, to better reach the Arabic language flourishness.

Summary

Yet to be completed...

Style
Description
sample
Pic
Kufi
(Diwan
kufi here)
Early time of Islam
3rd or 4th century
applied to the early scripts used to write the Koran
 difficult to write any long text
الإعجاب بالكتابة السحرية والمهارات Kufic script
Naskh
The script of choice for the Koran
Popular for writing books because of its legibility
Adapted for printing
The most common font in printed Arabic
الإعجاب بالكتابة السحرية والمهارات
الإعجاب بالكتابة السحرية والمهارات
Naskh style
Nastaaliq
Developed in Iran in the 8th and 9th centuries (wp)
Nas(kh)+Taaliq
الإعجاب بالكتابة السحرية والمهارات Nastaliq script
Reqaa
This script evolved from Naskh and Thuluth...
الإعجاب بالكتابة السحرية والمهارات Rekka font
Diwani
Used in the Ottoman court to write official documents
Difficult to read and write
Still in use today
الإعجاب بالكتابة السحرية والمهارات Diwani script
Thuluth
Support Harakat Indicators
Script par excellence for writing many different kinds of texts
Used particulary for titles and architectural inscriptions
الإعْجَابْ بالكِتاَبَةِ
السِّحْريَةِ وَالمَهَاراَت

Thuluth script
Rabat
aka Maghribi
Western Islamic world of North Africa and Spain
Used for writing the Koran as well as other scientific, legal and religious manuscripts
Not much used today.
الإعجاب بالكتابة السحرية والمهارات
Maghribi Script
Taaliq
 Arabic calligraphy designed for Persian language. Until replaced by Nastaaliq
الإعجاب بالكتابة السحرية والمهارات

Remarks

@@ Consider  readability and accessibility when styling and using newer fonts
@@ shapes and proportions font if mixed texts 

...

References:

[1] "Arabic Calligraphic Styleshttp://islamicart.com/main/calligraphy/,

[2] "الخط العربي (Arabic Calligraphy)http://www.alargam.com/languages/khat/khat.htm
[3] Wikipedia
    "الخط العربي " https://ar.wikipedia.org/wiki/%D8%AE%D8%B7_%D8%B9%D8%B1%D8%A8%D9%8A
    "Islamic Calligraphy" https://en.wikipedia.org/wiki/Islamic_calligraphy
[4] "Why It’s So Hard to Design Arabic Typefaces" http://www.wired.com/2015/10/why-its-so-hard-to-design-arabic-typefaces/
[5] "Butterick’s Practical Typography" http://practicaltypography.com/