A Process is a method of doing or making something and a Process Map is a diagram that shows the main steps involved in completing a Process.
A Process is a method of doing or making something, a series of actions - Activities, Decisions and Deliverables - which transform inputs into outputs.
For example, when making a cup of tea you start with a thirsty person - your starting Deliverable. Then you perform a series of Activities like boiling the kettle and selecting a tea bag and mug which create outputs like boiling water and tea brewing in a mug which are your Deliverables. You will also need to make Decisions such as whether to add milk and sugar and then you present your tea to a happy person - your end Deliverable.
A Process Map is a diagram which clearly show the main steps needed to carry out a process, plus any items produced by that process. Enabling anyone who views the map to carry out that process correctly first time.
In our example above the process of making a cup of tea has been 'mapped' below.