Enterprise IT: The systems that run the organization, basically everything run by an internal it group.

Legacy systems: Any old software systems, usually enterprise IT, that are running your organization. Often 80's era in big companies, usually on a mainframe and most importantly, even though they are held together by hopes and prayers they usually do the job they are supposed to.

Dev shop : derogatory term for a company who just provides developers, usually with poor oversight and project management controls.

The problem with hiring more people is if I need 20 Devs for six months in a language I am never going to use again, not only do I need to hire 20 Devs, I need to hire the project managers, people managers, pay for their benefits or contracts, and then figure out how to fire or otherwise reallocate people with skills I don't need.