This depends on whether you're using British or American English.

Oats is the name of the crop (Latin name avena sativa) A farmer who grows several cereal crops might grow wheat, barley and oats, for example.

In British English, we also use the word oats to refer to the flakes of oat you can buy at a supermarket - hojuelas de avena.

By cooking these oats with water and/or milk, you can make a creamy breakfast dish called porridge ( colada de avena). You can eat this the traditional Scottish way with salt, or if you prefer, with sugar, honey and fruit such as blueberries.

If the oats are ground down into a fine powder, this is called oatmeal. (farina de avena)

The issue becomes slightly confused by the fact that speakers of American English use the word oatmeal to refer to the creamy breakfast dish described above (colada de avena).