What is the use of :GetPlayerFromCharacter()?

So I am trying to make a simulator game and I don't understand how :GetPlayerFromCharacter works. I read https://developer.roblox.com/en-us/api-reference/function/Players/GetPlayerFromCharacter but I still don't understand. Can anyone explain what it does with low scripting vocabulary. Thank You

local function Sell(player)
	local blocks = player:WaitForChild("leaderstats"):WaitForChild("blocks")
	local coins =  player:WaitForChild("leaderstats"):WaitForChild("coins")
	local add = blocks.Value * multiplier
	coins.Value = coins.Value + add
	blocks.Value = 0
end

local function touched(Part)
	if game.Players:GetPlayerFromCharacter(Part.Parent) then
		Sell(game.Players:GetPlayerFromCharacter(Part.Parent))
	end
end

script.Parent.Touched:Connect(touched)

It returns the Player object controlling a given character. It's like the opposite of getting Player.Character.