What is the difference between manager purchase and purchase manager?

Answer 1

In English, the order of the words sometimes alters their meaning; often when two nouns are placed together, the first one becomes an adjective describing or clarifying the second one. This is the case here.

A purchase manager is a manager in charge of making purchases (of supplies or raw materials) for a company or division. They may sometimes make the purchases themselves, but often all they do is authorize a shopping list and budget for the actual buyers to use.

A manager purchase is a purchase which has been made or authorized by a manager. If the company requires a manager's approval before making certain purchases (such as land, or an expensive piece of equipment) this indicates that the permission was given, or that the manager went out and bought the item on their own initiative.