We are planning to migrate from a 2010 to a SharePoint 2013 server. In order to organise our libraries we use metadata such as search terms and document types instead of  folders.
With a migration to 2013 comes the opportunity do drag and drop (several) documents on the library page, or use One Drive for Business to upload/sync documents.Â
Does anyone know if, and if so how, metadata can be added to (several) documents when uploading them on SharePoint using One Drive For Business or drag-and-drop?
You have several options. You can use third party tools to assist with this or you can have your files defaulted to a particular term. There are third party tools that will also allow you to make mass changes if needed.