DevOps is a set of software development practices that combines software development (Dev) and information technology operations (Ops) to shorten the systems development life cycle while delivering features, fixes, and updates frequently in close alignment with business objectives. 
Agile software development has broken down some of the silos between requirements analysis, testing and development. Deployment, operations and maintenance are other activities which have suffered a similar separation from the rest of the software development process. The DevOps movement is aimed at removing these silos and encouraging collaboration between development and operations.
DevOps has become possible largely due to a combination of new operations tools and established agile engineering practices, but these are not enough to realize the benefits of DevOps.
Even with the best tools, DevOps is just another buzzword if you don't have the right culture.
The primary characteristic of DevOps culture is increased collaboration between the roles of development and operations. There are some important cultural shifts, within teams and at an organizational level, that support this collaboration.
By Rouan Wilsenach