Procurement Management consists of the following processes. See also Knowledge Areas - Procurement.
|  Plan procurements  ||Planning|
|  Conduct procurements  ||Executing|
|  Administer procurements  ||Monitoring & Controlling  |
|  Close procurements  ||Closing  |
Procurement Management involves getting work done by people outside the project team. Project Procurement Management includes administering contracts and change control process to manage contracts or purchase orders.
The project manager's role is to understand the procurement process, understand contractual terms, idenify risks and develop mitigations associated with the contract, adjust the schedule based on procurement process and/or contractual terms, etc.
Not understanding the terms of a contract can lead to potential issues on your project.
"Okay, wise guy. My contract SPECIFICALLY says I am always to be drawn AS A RABBIT!"   Bugs Bunny
Procurement planning involves determining what purchases will be needed to complete the project work. Many projects involve work being performed by an outside vendor. Thus, the project manager needs to plan for how the work will be performed as per contractual agreements, how communications will be handled with the vendor, what measures will be taken to inspect the vendor's deliverables to ensure compliance to project requirements and contractual obligations, etc.
During the Conduct Purchases process, proposals from sellers are evaluated. Once evaluated, a seller is select to perform the work and a contract is awarded.
Purchasing or bid documents are submitted by the buyer to the seller and are documents that serve as invitations to sellers, solicit offers and establish contractual terms.
The Administer Procurement process involves managing vendor relationships to ensure the seller's delivery meets the requirements as stated in the contract.
There are pros/cons associated with each contract type. Below are advantages / disadvantages to help you manage each type of contracutal relationship effectively.      Pros & Cons of Different Contract Types
The Close Procurement process involves verifying that all planned work has been completed as per the terms of the contract.