In a modern café menu, mocha usually means a combination of coffee, chocolate and milk. CoffeeBox describes the familiar version as espresso mixed with chocolate sauce or cocoa and finished with steamed milk. Foam, whipped cream and extra cocoa may be added, but those decorations are not the main distinction from a latte. The defining additional ingredient is chocolate.
The term also has older associations with the Yemeni port of Mocha and coffees traded through it. That history does not mean a mocha drink must contain Yemeni coffee or that every naturally chocolate-like coffee has added cocoa. A moka pot is another separate use of the name: it is brewing equipment, not a machine dedicated to making the chocolate beverage.
For a home version, combine the chocolate component thoroughly with the brewed coffee before adding milk. Record the amounts so sweetness and coffee intensity can be adjusted separately. Cocoa powder and sweetened chocolate sauce behave differently, so check ingredients rather than assuming equal quantities will give the same result. Concentrated moka-pot coffee can provide a home variation, while still differing from espresso. The balance you prefer is a recipe choice, not a requirement to use one roast level.

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