Shadow IT, with respect to big organizations, can be described as information technology systems that are deployed by any department, apart from the central information technology department, to explore whatever might be the shortcomings made by the central information systems. Shadow IT can also be referred to as fake IT, rogue IT, client IT, embedded IT, stealth IT, or feral IT.
The shadow IT systems are seen as an essential source of innovation, plus these shadow systems are very likely to become prototypes for a solution in central IT in the future. Shadow IT solutions, in contrast, brings risks with organizational requirements on an increment level with respect to control, security, documentation, reliability, etc.
In large organizations, information systems can be seen to be a source of frustration for the users. And the other departments in the organization would come up with independent IT resources so as to avoid the limitations that come with the solutions provided by the central IT department.