Hey Dyocs,
課時 means hours of class
班級 means class
Eg.
因為我們每一個禮拜只有兩個課時,所以我們能做的事很有限
There is a limit to what we can do because we only have two hours of class each week
張老師擔任三個班級的地理課,每週共有六課時
Mr. Zhang is in charge of the geography lessons for three classes and in total teaches 6 hours (or classes) each week
我們班級一共有30個學生
There are 30 students in our class
小王在班級裡的成績最差
Xiaowang has the worst grades in his class
Laurence