There are literally hundreds of different hechshers, or kosher certification symbols, that appear on foodstuffs, beverages, and dining establishments of all types around the world. The sheer array of these kosher stamps of approval can be mind-boggling even to consumers who keep kosher for religious reasons and who are well-versed in the kosher laws.

The "Big Four" are the largest kosher supervision establishments in the country. These include Organized Kashrut Laboratories (better known as "the OK"); the Orthodox Union (OU), one of the oldest and largest Orthodox Jewish organizations in America; the Kof-K, the first kashrus organization to introduce computer technology to the complexities of kashrus supervision/management; and Star-K, which originally served the Baltimore Jewish community exclusively.

There are plenty of lists of reliable hechshers, usually organized geographically, but they're quite lengthy and can be tough to slog through. This overview of lists by hechsher type can provide a helpful breakdown of the different types of hechshers and the organizations that provide them. Each ever-evolving list highlights major players in kashrut supervision, photos of their hechshers on actual products (instead of black-and-white logos), agency history, contact information, and more.