This is the 4495th most frequent Russian word.
вузах
"Вузах" means "in higher education institutions" or "in universities."
In this sentence, "вузах" is the plural locative form of "вуз," which means "university" or "higher education institution." It indicates the place where the action of studying occurs: in universities.
Студенты обучаются в вузах разных городов.
Students study at universities in different cities.
Here, "вузах" is used to describe the location related to the subject being discussed, specifically education quality in higher education institutions. It is again the plural locative form of "вуз."
Качество образования в вузах становится одной из главных проблем.
The quality of education in universities is becoming one of the main issues.
In this case, "вузах" indicates the physical setting of the events, pointing out the universities where the conference is set to occur. Again, it is the plural locative form.