One of the dangers of loops is an infinite loop. You get into an infinite loop when the condition of the loop never evaluates to false. Because the condition keeps being true, the loop goes on forever. The following code snippet demonstrates a simple infinite loop:

while true do
    print ("forever")
end

A more real-life example of an infinite loop would look like this:

x = 10 -- Initialize a "control" variable

while x > 0 do -- Boolean condition: x > 0
    print ("hello, world")

    x = x + 1 -- Decrement the "control" variable
end

This loop will run forever, since the value of x keeps increasing and will never reach 0.