As per traditional IT process-
DEV | Ops
Imagine the vertical line as a silo between the Development Team and the Operations Team.
To deploy new applications or to deploy enhancements to a current running one developers used to volley their codes over this wall to the court of Operation's team. So collaboration between Dev and Ops was minimal which resulted in issues viz. " Work in test but why the heck its not working in production environment".
This led to frustrations, reinventing the wheel on various counts, multiple reviews, delays in timelines which eventually impacted the ROIs
Hence
To negate the above mentioned issues the need of the hour was to bring in a process which infuses a sense of collaboration, innovates to inculcate automation at various stages wherever feasible.
So the silo was broken down resulting in
DEV-------------->>> is moving towards OPS
&
OPS-------------->>>>>is moving towards DEV
Hence the evolution of "DEVOPS"