bootstrapping is not related to linux, ALL operating systems boot. basically there needs to be a way to get an operating system running, or booting. and this term covers those actions.
bootstrapping is an analogy from the air forces, presumably WWI, relating to the fact that before a fighter pilot can take off and fly, and will make sure his boots are firmly strapped... simple as that.
if you are having a specific problem starting linux, please provide more details.