What is the roll of procurement in the organisational structure?

When I enter the word procurement in the dictionary it says "the act of getting possession of something" that link to a word acquisition which is " the act of contracting or assuming or acquiring possession", which again links to the word purchasing which is defined as "the acquisition of something for payment" linking to a word buying which is " the act of buying" which link to the word shopping which is "searching for or buying goods or services", it makes one wonder....