Essay presented in 2017 as fulfillment of requirements for completion of the module INM304 - Digital Libraries, part of the MSc Library and Information Science course at City, University of London. Abstract: In this essay, I first take a look into some existing definitions of 'digital library', attempting to identify the continuities and changes they presented over time, and to understand the reasons why the term has always been under revision. I then recognise a great divergence between the various definitions when it comes to trying to describe what a 'digital library' is made of: 'digital documents', 'information entities', 'data'? I argue for an agreement on the idea that a 'digital library' contains 'digital objects'; I explore this ...