Can someone explain gayrimenkul kimliği means?

The best I can do is ´real estate identification´?

What´s the difference between gayrimenkul and emlak?

Here is my guess: Menkul´s root is nkl in Arabic and "nakil etmek" (nakletmek) means to transport in Turkish. So I think "menkul" must mean something transportable and gayri means "except" or "non" in Turkish. So here it must mean non and gayrimenkul must mean "non transportable". Emlak comes from Arabic root mlk. We have mülk in Turkish. It means possession. Emlak must be plural of it. So it means possessions. But in Turkish we use emlak for buildings, houses, places. So they are non transportable too. That is why I think two words have similar meanings.

I´d say a gayrimenkul kimlik is a property ID like what you´d see listed next to an online property advert.

gayrimenkul is realty i.e. property whether it be residential, commercial etc. Old Arab word used for items you can´t transport/carry. Ironic since we have mobile homes thesedays but think way back when.

emlak literally translates as ´estate´ so can mean land, farms etc. however, easy way of thinking of it - an Emlak will sell you your Gayrimenkul. 

Great explanation.. but what about taşınmaz which is a pure Turkish word and widely used in place of Arabic gayrımenkul ?

I think the best English equivalent for Turkish(?) menkul is mobile.

German immobilien has exactly the same sense as gayrımenkul (=>taşınmaz) 

In Dutch the generally used word is "onroerend", "on" meaning "not" and "roerend" meaning "moving".

Onroerend goed: 

•   literal meaning: non-moving object
•   general meaning: real estate.

(Ofcourse nobody is learning Dutch but it´s fun anyway isn´t it)