This is the 3019th most frequent Russian word.
завершение
Completion; conclusion; end.
Here 'завершение' is used as a noun referring to the process of completing a task or project.
Завершение проекта займет ещё немного времени.
The completion of the project will take a little more time.
Here 'завершение' is used as a noun indicating the time point or event of finishing an activity like a lesson.
После завершения урока учитель ответил на вопросы.
After the completion of the lesson, the teacher answered questions.
Here 'завершение' is used as a noun signifying the conclusion or end of an event, in this case, an exam.