In the United States, a slow cooker is commonly referred to as a "Crock-Pot." The name "Crock-Pot" is actually a trademarked brand that has become synonymous with the appliance itself. The Crock-Pot was one of the first and most popular brands of slow cookers, and over time, the name has been widely used to describe any similar cooking device, regardless of the brand.
So, when Americans talk about using a slow cooker, they often use the term "Crock-Pot" interchangeably to refer to the appliance. It's important to note that while Crock-Pot is a well-known brand, there are many other manufacturers that produce slow cookers with similar functions and features.