Definition:
Educational Instistution with different from schools for children and youth organisation of education. Persons aged 18 or oldeer (as well as those who will have been 18 in the calendar year in which they are admitted to a school) are admitted to these schools.

Source:

• Act of 7 September 1991 on the Education System
  Place of publication: (Dz.U. 2019 poz. 1481)

Low-level terms:

• General secondary school for adults
• Primary schools for adults