The difference between these drinks has been a point of confusion for many in the coffee world, so let’s break it down simply (and yes, you’re right it has a lot to do with the amount of milk in the drink):
An espresso macchiato is made by adding a splash of milk to a shot of espresso. Macchiato literally translates as “marked” referring to how the espresso is marked with a dash of milk. These days you can find variations on the classic macchiato like a caramel version or an inverse macchiato which is hot milk with a small splash of espresso.
This inverse macchiato is also called a latte macchiato and this is where some of the confusion with the coffee maker may have started. Nonetheless, a macchiato, a latte, and a latte macchiato are all different drinks.
A cappuccino is made with a 1:1:1 ratio of coffee, milk, and milk foam. This classic coffee drink gets its name from the Catholic order of Capuchin monks since the color of the drink matches their robes. Cappuccinos are immensely popular all over the world and flavor additions like vanilla and hazelnut are common. Traditionally, cappuccino is a morning drink but not everyone follows this outside of Italy.
A latte is also made of coffee, milk, and foam but the ratios are different than a cappuccino. A latte has much more steamed milk and less foam than a cappuccino (around 15% coffee, 85% milk). Lattes are also very popular all over the world and many variations exist. Since ‘latte’ just means milk, be careful while ordering a latte in an Italian café because you’ll be served a glass of steamed milk.
To sum up, you can describe the drinks as follows:
A macchiato is an espresso with only a splash of milk.
A cappuccino is made with equal parts coffee, milk, and foam.
A latte is made with coffee and milk, with more milk than coffee and very little foam on the top.
Hope this helps!