There are various types of Turkish bağlama/saz, but we will summarise the most common types as below from the smallest to the largest in size. It is important to note there are various tunings and fret numbers, especially with regard to tempered frets based on the geographical origin of the saz, so here only the most standard and common types are listed:
Cura
Tunings: ADD, ADE, AEB.
Kısa Sap (short-neck) bağlama
Tuning is written as AGD, however the actual tuning can be CA♯F or BAE;
It has 19 frets
Uzun Sap (long-neck) bağlama
Tuning is written as GDA, however the actual tuning can be AEB, A♯FC and CGD;
You can turn a long-neck bağlama into a short-neck one by tuning the saz to AGD and placing a capo on the 4th fret, thus achieving AGD;
It has 24 frets.
Tanbura/Tambura (also called Saz, Bağlama, Bozuk, Çöğür)
Tuning is like long-neck bağlama
Divan Sazı
Tuning is ADG;
It has 24 frets.
Meydan Sazı
Tuning is ADG;
It has 24 frets.
There is also a Azerbaijani variety of saz, also called qopuz in Iranian Azerbaijan, and played by Azeri ashiqs:
Azerbaijani Saz
Tuning is ??
It has around 18 frets, some of which are placed on the soundboard
?? http://www.turkuler.com/baglama/duzen.asp