<prompt> Translate the following text to EnglishTofauti nyingi muhimu kisheria hutenganisha wageni kutoka kwa raia na uchunguzi wa usalama wa kitaifa kutoka kwa uchunguzi wa utekelezaji wa sheria.  <response>: A host of legally significant distinctions separates aliens from citizens and national-security investigations from law-enforcement probes. 