Can students submit an assignment directy through the platform?

Of course, for allowing students to submit assignments through the platform you have to add the assignment activity in your course. For this, click on Add an activity or resource and choose Assignment: you will be able to choose a lot of settings as the start and end date for submissions, the possibility to sumbit beyond the deadline, the assessment scale, etc.
Once done, students will be able to upload their assignments and you will be able to grade them directly through the platform (see this FAQ: Is it possible to grade assignments through the platform?)

(last update: 03.08.2018)