Question regarding pommes puree and mashed potatoes?

You're right on the money... Pommes is basically how you described it. A puree of potatoes whereas mashed potatoes are drained of liquid before they are smashed and then you add your dairy or liquids. This gives a fluffier textier. When you leave mostly liquid and puree the potatoes, you work the gluten in the starches and create a gummier texture..... This is why you try to avoid over whipping your mashed potatoes.... Both are delicious if seasoned properly and both have appropriate accompaniments....hope this helps.