PFI stands for the Private Finance Initiative. It is a British government idea, strongest in the 1990s and 2000s: a private company builds something the public needs — a hospital, a school, a road, a prison — and often runs it too. The government does not pay the whole bill up front. It pays the company back, slowly, for many years, like a very long hire. The promise was: the country gets the building now, and the cost is spread out. Though actually, a lot of people later said it was a poor bargain. The total bill was often much higher than if the government had simply borrowed the money and built the thing itself, and the contracts were so tight that changing a hospital ward could cost a fortune. You will meet PFI in UK news and politics, not in everyday chat. It is a formal policy name. Many countries have a cousin of this idea called a public–private partnership; PFI is the British brand of that story.