What is the Drop Box tool?
From EdTech Help
The Drop Box tool creates a folder for each student in the course. Students are only able to access their own folder. Students and instructors can both place files in the Drop Box folders.
The Drop Box mirrors the file management features and functionality of the Resources tool. See What is the Resources tool? for more information on how to add, upload, edit, and delete files and folders within Drop Box. (As with Resources, multiple files can also be uploaded using Drag and Drop.)