All References include all references in your Mendeley library, However, you can use collections to organise your library.
Find how to annotate PDF documents from the Mendeley Reference Manager online guide.
When you make notes to a PDF document, a click on the article in your library will show all annotations you made to the PDF. You can also make a general notes (e.g. a brief summary of this article) for this document.
Notebook is a new note taking tool from Mendeley Reference Manager. You can create notebook pages for different topics and use them to collect annotations and highlighted text from PDFs as you read them.
You can highlight or add notes in a PDF document saved in your Mendeley.
You can sync your desktop library with your Mendeley Web library. This ensure that you can access to your Mendeley online from other computers. Syncing is also a way to back up your desktop library to your online library in the cloud.
If you are signed in to your Mendeley desktop, your references and documents should automatically synch with your Mendeley Web, to ensure your library remains consistent and current.
To check whether the synch process is working correctly, add a document to your Mendeley desktop library. Press the synch button and wait for the document to synch. Log in to your Mendeley Web account and check whether the document has been added to your online library.
You might prefer to disable the automatic synchronization that is the default setting of Mendeley, for example if you have a limited internet connection.
It is possible to adjust the automatic synchronisation from within your Mendeley desktop library, by clicking Edit Settings.
You can uncheck the synchronize attached files box. Be aware though that you will need to apply this change by clicking Save and Synch. Doing this will remove existing PDF's from your Mendeley Web. You can check the same box again later to reload them from your desktop Mendeley to Mendeley Web, but if you have large numbers of PDF's/attachments, then this process may be very time consuming.
Another option might be to choose which folders you want to automatically synchronize, and which you don't by changing the synchronize process from entire library to selected folders. Only the folders that are checked will be synchronized.