The term American Judaism is not as clear as it might seem at first glance. Not too long ago the term Judaism seemed clear enough. People might disagree about its specific contents but agree that Judaism referred to the norms, values, and beliefs that characterized the Jewish religion. There were those who argued that Judaism was basically a culture rather than a religion, and some even argued that the term civilization was more suitable. However, at its core, Judaism - whether a religion, culture, or civilization - contained a set of norms, values, and beliefs, many of which, all would agree, referred to God and to the relationship between the Jewish people and God. These norms, values, and beliefs existed independently of how individual Jews behaved or what individual Jews believed. In other words, there was a structure or an essence called Judaism, and the behavior or beliefs of individual Jews could be measured by the extent to which they conformed to or deviated from the norms and beliefs of Judaism.

Within the confines of these norms existed differences between Judaism in different societies. American Judaism meant the particular customs, or emphases, or variations that were characteristic of the manner in which Judaism was practiced in the United States, distinct from the practice of Polish or German or Yemenite Judaism. This set of understandings had important implications, most especially for differences between the various Jewish denominations, that is, the Orthodox, Conservative, Reform, and more recently the Reconstructionist movements.