While trying to get fare and schedule information on the Kamilkoc web site I came across three bus stations for Istanbul.
Istanbul Otogar
Istanbul Alibekoy
Istanbul Umraniye/Oudullu

Other research indicates that there are two main bus stations in Istanbul. One is called
The Büyük Otogar (Grand Bus Station), also known as Esenler Otogar, located in the Bayrampasa district. It is 10 km away from Sultanahmet Square.
The other bus station, Harem Otogar, is located on the Asian side in Üsküdar.

So can someone explain (a) why don't the names match? and (b) which of these 5 station names are synonymous? (if at all )

Thanks so much.

Istanbul Otogar means the major bus depot at Esenler

Alibeykoy and Umraniye/Dudullu are way stations that Kamil Koc has where they can drop and pick passengers either with the bus directly or a smaller transfer vehicle.

Umraniye/Dudullu is on the Asian side. Alibiyekoy is on the European side and has shuttle services to sultanahmet, taksim, vs. Istanbul Otogar is the main station located in Esenler which has a metro to Ataturk airport.

otherchelebi and sedaa91

Thank you very much.
Will be in Istanbul next week - really looking forward to it.