For me, the main characteristics of the many of the available definitions of digital literacy are that:
it supports and helps develop traditional literacies – it isn’t about the use of technology for it’s own sake or ICT as an isolated practice
it's a life long practice – developing and continuing to maintain skills in the context of continual development of technologies and practices
it's about skills and competencies, and critical reflection on how these skills and competencies are applied
it's about social engagement – collaboration, communication, and creation within social contexts