What does 'return' do and how can I use it in my games?

I've been learning how to script this past week and I came across a lot of different terms but the one that confuses me the most is return. I've looked at multiple videos and websites to help me understand what returns are and what there used for but I'm still having trouble wrapping my head around it. If you can explain to me what returns are and how are they used in games I would really appreciate it.

Functions aren't just reusable chunks of code. They can also "return" values. A (basic) example is this:

function addfive(n)
	return n + 5
end

local ten = 10
local fifteen = addfive(10)

print(ten, fifteen)

Returning is not limited to numbers. You can return anything. How about this function that finds a part which has the color "Really red"?

function findRedPart()
	for _, v in pairs(workspace:GetChildren()) do
		if v.BrickColor.Name == 'Really red' then
			return v
		end
	end
end

local redPart = findRedPart()
redPart:Destroy() -- i hate red parts!

Or this function that returns a table of red parts???

function findRedParts()
	local redParts = {}
	for _, v in pairs(workspace:GetChildren()) do
		if v.BrickColor.Name == 'Really red' then
			table.insert(redParts, v)
		end
	end
	return redParts
end

local redParts = findRedParts() -- now i can have all the red parts and destroy them all

The oppurtunities are limitless...

Though I'm sure someone else is gonna explain it better than me, that's the best I can do. I hope this helped a little.

The return keyword can do either 1 of 2 things or both things:

1. Ends the current thread function

2. Makes a function return a given value

If you give return nothing to return, it'll just end the function:

script.Parent.Touched:Connect(function(hit)
	if game.Players:GetPlayerFromCharacter(hit.Parent) then
		print(hit.Parent.Name)
	else 
		return -- The function would end here
		print("nothing found")
	end
end)

If you give return a value, it'll make the function return that value AND it will still end the function:

function GetTouchingPlayer(hit)
	if game.Players:GetPlayerFromCharacter(hit.Parent) then
		return hit.Parent.Name
		print("player found") -- This will not print because the previous line ends the function
	end
end
script.Parent.Touched:Connect(function(hit)
	local var = GetTouchingPlayer(hit)
	print(var)
end)

return cannot be used to end statements.