The Digital Humanities are expanding every day and as such so is its definition. Below are several definitions from experts working in the field.
Digital humanities is the application of digital tools and processes to the study of humanities disciplines resulting in new efficiencies and new discoveries that are not obtainable in the analog world.
-Sue Perdue, Virginia Foundation for the Humanities/Documents Compass
For me, DH is about creating digital toolsets that allow users to undertake new forms of research in the humanities. Just as importantly, it's about making sure we build a deeper understanding of what's changing in the wider world as digital content and interactions become central to our personal and professional endeavors.
-Paul Gooding, University College London
[It is] the use of technology for supporting long term digital preservation of the human record, and enabling innovative methods for accessing it. [It is] the creation of digital infrastructure to support the work of researchers and scholars in the humanities. It also involves the development of computing approaches to humanities disciplines, mutually enriching humanities and computer scientists. In my opinion, Nicholas Negroponte, (MIT Media Lab co-founder), eloquently captures the scope of DH by stating: Computing is not about computers anymore. It is about living.
-Carlos Monroy, Rice University
I would define it as the intersection between computing technologies and research and teaching in the humanities. Influenced by web technologies, it also promotes collaborative approaches to scholarship.
-Alexandra Guerson, University of Toronto