Merhaba.

This is a piece of a message I got:

ya acıkcası bu sene hazırlık okuyacağım...

"well, frankly this year I will study (read?) preparation..."

What does it mean to "study preparation"?

Is it a kind of an idiom?

Prep School (Preparatory School) offers a usually one year course to teach the language that will be necessary to follow the lectures in undergraduate classes. It is before the Freshmen class.

So, hazırlık should be considered a type of schoo/class, right?

correct.

I suppose it may be a shorthand for "hazırlık okulu"?

hazırlık sınıfı: preperation class, prep class, prep. Only a foreign language is studied there.

hazırlık okulu: preperation school: all prep classes in one building seperate than other buildings usually seen in universities. mostly foreign language courses all year long go on there.

preparatory year/junior collage/tertiary preparation/remedial education