A gap year is a year taken deliberately between school and university, and it is little known in Turkey.
Two kinds of gap year
The planned kind: how the year will be spent is known in advance. Work, volunteering, a language, a project, or retaking an exam.
The unplanned kind: a year taken because no decision could be made. That second kind usually ends in loss, because free time does not turn itself into a plan.
How it is arranged
There are two routes. The first is to accept an offer and ask the institution for a deferral. Many universities allow this and hold the place for a year; the conditions are on the institution's own pages and some require that no other institution is enrolled in that year.
The second is to spend a year without applying and apply the following year. That allows the file to be strengthened but guarantees no place.
How it is read in an application
It is not read negatively. What is read is the content of the year: what was done and what was learned.
A year of travel is a weak story on its own. A year working, running a project or building a skill is a strong one.
The exam side
Two things are checked for a student taking a gap year: the validity period of the language certificate and whether the exam scores will still be accepted at the moment of application.
A certificate valid for two years may have expired by the end of the gap year. That is the most commonly overlooked detail.
The real risk
Losing the working rhythm. A student who spends a year away from academic work can struggle in the first term of university.
That is reduced by keeping some academic work going during the year, and it should be considered at the planning stage.