Project Management has been around since early civilisation, take for example the building of the pyramids nearly 5,000 years ago. Essentially a Project is a linked set of tasks that is organised, planned and implemented in order to achieve set goals or objectives in a fixed time period.
They all involve people striving to achieve some unique end goal in a given period of time. Projects are temporary by nature as opposed to routine, repetive activities that make up many day to day business transactions.