This book shows how many previously contingent social processes have gradually been re-organised and transformed into entangled processes of 'discontinuance' and 'continuance' through the implementation of digital logic. Together with the necessary co-evolution of our collective digital literacy, this persistent process of transformation throughout modernity is theorised here as one of 'social digitalisation.' Social digitalisation highlights the ways in which material digital technology, like preceding material technologies, has been fitted into the longer term trajectory of digital transformation. This new social theory thus reverses prevailing accounts of the 'digital revolution' that focus exclusively on changes allegedly caused by material digital technology in recent decades. The book also demonstrates the fruitfulness of applying the theory of social digitalisation as a holistic approach in researching the wide-ranging consequences of contemporary digitalisation, including its contrasting effects on different social groups. It will be useful to students and researchers of sociology, communications, media and history, but also for general readers interested in understanding the overall complexity of digitalisation and how digital transformation has come to dominate the ways we live today.