Diachronic and Synchronic approaches

A diachronic approach is one that analyzes the evolution of something over time, allowing one to assess how that something changes throughout history. You would use this approach to analyze the effects of variable change on something, thus allowing you to postulate WHY a certain state was borne of a prior state or WHY a certain state progressed to some future state. An example: you could use a diachronic approach to determine why the USA government has come to develop a system of political parties despite the fact that the founders mistrusted political parties and did not create them.

A synchronic approach analyzes a particular something at a given, fixed point in time. It does not attempt to make deductions about the progression of events that contributed to the current state, but only analyzes the structure of that state, as it is. Example: one might use a synchronic approach to describe the state of political parties in the USA at some specific time, analyzing their structure and functions only as they relate to the specific state that they were in at that time.