Both of these words in the dictionary have themselves defined as “snack” but what are the differences between these 2 words?
小吃: snack. Examples: steam bun, hot dog, baked sweet potato (most street food stall's cooked food are considered 小吃.) There are also cold served 小吃 like cold cut meat or cheese on cracker (mostly served in parties)
零食: snack/ junk food. Examples: chips, candies
Most noticeable difference: We call 零食 junk food but not 小吃
小吃 is more like some freshly cooked food, usually served hot or warm.
零食 are things like chips, candys and will not be served hot in general.
And to my understanding of English, snack is more like 零食。