Soap

I was reflecting recently on how many kinds of soap there are. Not just brands of soap, or scents, but the actual forms that the soap may take. For example, most people are familiar with bar soap, and then there's shower gel, and liquid soap, and foaming liquid soap, and the granular soap that is usually dispensed in less-well-kept public bathrooms. I've found, however, that most people in the US are not at all familiar with a certain sort of soap that is an opaque jelly that comes in plastic tubs. In fact, I've only ever seen it in developing countries. When I questioned some coworkers about it, none of them had even heard of the soap that comes in a tub or jar. Does anyone know why? Is it considered somehow a sort of lower-class or "third world" soap? Just wondering.