Caro's spent twenty years writing Beth Yosef, a commentary on  Rabbi Yaakov ben HaRosh's work Turim. In this gigantic work, Caro presents Talmudic arguments for each topic and then explains the reasons for the Halachic decision. 

The Shulchan Aruch, an abridgement of Beth Yosef, was a short digest of all Jewish laws. The Shulchan Aruch described, in concise language, what Jews were supposed to do in every circumstance. He called the work Shulchan Aruch (Prepared Table) because it brought Jewish Law in a orderly way to all who wanted to get it.

One reason the Shulchan Aruch became so influential in the Jewish world was because it was the first code to be printed on the printing press. It was printed in 1565 and distributed around the Jewish world.

Moses Isserles, a great Polish rabbi, added a commentary called Mappah (Tablecloth) of Ashkenazi customs to the Shulchan Aruch in 1569. After several more commentaries and editions, the Shulchan Aruch became the universally accepted code of Jewish law.