An ebook which the libraries have purchased, or which is freely available on the web. See the sections on Finding and Using ebooks for information on these.
The electronic equivalent of a 'library use only' print book - UK publishers donate us these texts because we are a Legal Deposit library. They can only be read on library computers (not your own laptop) from within one of the Bodleian Libraries. See the full eLD LibGuide for information on these items, including printing, and the tab on citing ebooks. The rest of this LibGuide does not apply to them.
There are a number of benefits to using ebooks:
If you are struggling with something, you can contact your subject librarian (see this list), or Hilla Wait, who is the Chair of the Ebooks Steering Group within the Bodleian Libraries.