The Multiselect feature in the library page allows you to select and perform actions on multiple items (projects or media) at once.
Next to the respective entity sections, you’ll find the button 
which, once clicked, activates multiselect.
Actions You Can Perform with Multiselect
Depending on the type of item, the actions that can be performed using multiselect are:
- Delete: for folders and projects
- Download: for media
- Move to folder: for projects
To learn more about what Projects and Media are and how to create folders in Contents, check out the guides Media and Projects in Contents and Creating and Viewing Folders