if you did something wrong and want to say you are sorry for it, you can say "bocsánat" and "sajnálom". in this case "bocsánat" is somewhat neutral, "sajnálom" emphasises your regret, that you really feel bad about it. if you step on someone's toes you say "bocsánat" or "elnézést". if someone is in your way and you want them to let you through, you say "elnézést". does this answer your question?