"Professor and students"
Translation:Викладач і студенти
"Викладач" is a higher ed "teacher". We have вихователь(ка) in kindergarten, вчитель(ка) in school and викладач(ка) in university. Професор is an academic title and position in schools of higher education. So only some викладачі (rather small number of them) are професори
As far as I remember, there are a couple protagonists that are also teachers while being 'Professors' at the same time because most of them are the head of their houses. Notable examples being Professor McGonagall, Professor Snape and the iconic Professor Dumblebor.
This is just in regards to the Potterverse lore, we must also keep in mind that not all of the teachers at Hogwarts are professors.