Que signifie local dans Roblox

-- A local variable is accessible only in the block where it’s declared. 
-- Local variables are declared using the local statement:

function add(number)
	local myNumber = 50
  	myNumber = myNumber + number -- This will work because is Inside the code Block
end
myNumber = myNumber + 10 -- This wont work because we cannot access it
The Real One