This report offers a brief overview of the literature on the defining characteristics of democracy in the 21st century. This report seeks to map out a range of conceptual approaches to understanding democracy, evidence on emerging trends in democratisation, and challenges to realising democracy in its varied forms. The report begins with a discussion on definitions of democracy that have emerged in recent decades (Section 2), highlighting a range of qualifiers that are widely used to differentiate and analyse different democratic regime types. Section 3 summarises trends in key indicators of democracy from widely cited observers – The Economist Intelligence Unit and the V-Dem Institute – and recent trends in public opinion towards democracy, according to World Values and Pew Centre surveys. Section 4 gives a very brief overview of three leading challenges to democracy discussed widely in the literature – gender inequality; the role of media and social media; and declining quality of elections, freedom of expression and civic space.