By now, you may realize that much of the work that goes on in the world is project work. If you schedule, track, or manage any of this work, then congratulations are in order: you are already doing some project management work!
Project management has been a recognized profession since about the 1950s, but project management work in some form has been occurring for as long as people have been doing complex work. When the Great Pyramids at Giza in Egypt were built, somebody somewhere was tracking resources, schedules, and specifications in some fashion.