What's the difference between a "simple lesson" and a "complex lesson"?

A simple lesson is an independent lesson (not linked to any other lesson on the grid, either by superimposition or succession), bringing together a teacher and an entire class in a single class meeting..

A complex lesson is a lesson made up of several class meetings, which can be linked to each other in a variety of ways; you decide how these class meetings are linked when you fine-tune the complex lesson.

When you start the automatic placement of lessons in the grid, you place the complex lessons first, then the simple lessons (the largest lessons first, then the smallest in the remaining gaps).

To easily identify complex lessons in your database, go to the display Timetable > Lesson > List, the activate the command Extract > Extract the complex lessons (via a right-click or in the menu at the top left of your screen).