If you are a Vtiger CRM user who also uses Dropbox, then you can easily access your documents in Dropbox directly from the Vtiger CRM.
When you upload a file to Dropbox, you will also have a record of the upload in your CRM account. This way, you can access your documents from your CRM account, and you do not have to log in to different online storage apps.
To know more about Dropbox + Vtiger CRM, click here
To know more about Dropbox, click here