Hashem relays the message through Moshe to Bnei Israel and says: USHMARTEM ET CHUKOTAI VE’ET MISHPATAI ASHER YA’ASEH OTAM HA’ADAM VACHAI BAHEM…, “You shall observe My decrees and My laws which man shall carry out and by which he shall live…”. (Lev. 18,5) It should be noted that the Torah does not say a Jew should carry them out but rather a man should carry them out and live. This means that it refers to all mankind.
CHUKIM or decrees are generally explained as those dictates for which we have no explanation or understanding and observe them because we are commanded to do so. These decrees are obligatory only on Jews. MISHPATIM or laws, on the other hand, are dictates for which we can understand their purpose and all society must abide by them. They are not directives targeting only Jews.
There is, however, a difference between the observance of laws by non-Jews and Jews. A Jew observes them because it is a command from Hashem. A non Jew observes them because of what is known as a “social contract”, an agreement among people to observe them in order for a society to be able to survive.
That is what the Pasuk means when it says a “man shall carry out and by which he shall live”. All men carry out the laws so that society can survive but a Jew carries them out because he is commanded by Hashem to do so.