Pierogi vs. Pirozhki

Pierogi and Pirozhki Definitions
Pierogi
A semicircular dumpling with any of various fillings, such as finely chopped meat or vegetables, that is often sautéed after being boiled.
Pirozhki
Small pastries filled with finely chopped meat, vegetables or fruit baked or fried, from eastern European cuisine, or a serving of these.
Pierogi
(North America) A square- or crescent-shaped dumpling of unleavened dough, stuffed with sauerkraut, cheese, mashed potatoes, cabbage, onion, meat, or any combination of these, or with a fruit filling.
Pirozhki
A single such pastry.
Pirozhki
Small fruit or meat turnover baked or fried