This emoji represent a cup with some beverage (most likely coffee), which is producing steam, meaning that the contents of the cup is hot enough. The [URL /ru/26FE/ cup] can be depicted with or without a plate.
Such a sign can be a warning that you may get [URL /en/1F525/ burned]. Coffee or tea is often sold in insulated [URL /en/26FE/ cups] with a lid. And this warning is usually printed on such lids, so that the seller doesn't have to repeat "[URL /en/2621/ Careful], the beverage that you are about to enjoy is extremely hot".
Also the coffee symbol may denote a cafe on a map or a sign, or be used for chatting on the Internet.
- Let's get a coffee. ☕
Besides, the popular programming language Jas was named after the coffee brand Java, that's why its logo demonstrates a cup of hot coffee.