DevOps is a set of practises that practically involve frequent deployments, fast cycle times, low release overhead, short feedback paths, quick time-to-restore, and so on.

It's an extension of lean manufacturing to software development, where the focus is on continuously pushing tiny packets of functionality to customers (instead of occasionally pushing huge bundles of features), to react quicker to changing demand and mistaken assumptions.

It is in no way "a sysadmin with scripting skills" -- the name for which, is, by the way, just sysadmin. Sysadmins know how to write Perl and shell and Python and have done so since forever.