It's a bone of contention for anyone who's a native speaker of Polish. Just go to Hamtramck or Little Poland in Chicago and wait until someone says "Pierogis". Guarantee you, every Polish person within a half-mile will feel the disturbance in the Force and come with pitchforks and torches...
My favorite variety are the homemade ones filled with potatoes and cheese, boiled (not fried) in salt water, then topped with fresh-off-the-pan bacon bits. My Babcia in Poland still makes them like that to this day, and I count down the seconds to the next time I see her since she knows how much I love her cooking
Had to google it, and surprise! Common food here in Romania too. Most common I eat are filled with salted cheese, and covered with pepper powder just a bit fried in hot oil. Yummy!
I had to look those up to see what they are. And they appear to simply be the polish version of Gyoza (Pot Stickers), which are also boiled (more like simmered) until the liquid is mostly gone then fried in oil (oil is added directly to the pan).
What is confusimicating you?