What's the difference between Arabic and Turkish tuning?

Can I tune my Arabic oud to Turkish tuning? Can I tune my Turkish oud to Arabic Tuning? 

As regards strings, the differences between Arabic and Turkish-style ouds can be be very confusing. Both styles can share the same scale length, soundboard thickness, soundboard response and playability.

Basically, the only single factor differentiating Turkish ouds and the Arabic variety is the fact that Turkish ouds are tuned one whole step above Arabic ouds. The tuning patterns are the generally same (mainly 4ths--see below). Since Turkish tuning is higher, it will increase the tension that the strings exert on the face of the oud.

For this reason, it is not advisable to tune an Arabic oud up to Turkish tuning. Doing so can severely damage the oud!. If for some reason you wanted to tune an Arabic oud up a whole step, you would need a custom set of strings.

However, it is perfectly fine to tune a Turkish oud down to Arabic tuning, although the resulting string tension may be too low on standard string sets. A custom set might be necessary for ideal sound.