As knowledge management (KM) and information technology (IT) have developed and grown, they have evolved numerous technical terms and phrases that those not intimately involved in these disciplines may find difficult to understand. These terms are useful in efficiently communicating among professionals, but they can be difficult to absorb in a rapid manner, and it can be difficult to obtain consistent definitions. There is a spectrum of tools to address different aspects of the jargon development phenomenon. At the low end of the range are lists that define each letter of an acronym but do not usually provide much else—they are essentially data-level tools. Many glossaries provide short definitions of terms and phrases; they are essentially information-level tools. Unless one has an idea or context already, it is difficult to truly understand when only provided with information. This encyclopedia addresses a void in the present spectrum. It is an attempt to create and distribute a knowledge-level tool, although it is not as voluminous as a full-boat encyclopedia (which would be impossible to adequately distribute). This encyclopedia was constructed using a number of different sources. Much of it, however, is tacit knowledge taken from my experience on-the-job at the Program Executive Office for Information Technology (PEO-IT), the Department of the Navy (DON) Chief Information Office (CIO), and from courses taken at the Information Resources Management College (IRMC) to achieve certifications (CIO and National Security Telecommunications and Information Systems Security Instruction [NSTISSI] 4011).