noun
crab
General term for crabs, including both edible and non-edible species. Often used in cooking contexts.
冬はカニがおいしい季節です。
Winter is the season when crab is delicious.
海岸で小さなカニを見つけた。
I found a small crab on the beach.
エビ refers to shrimp/prawn, while カニ refers to crab. Both are crustaceans but differ in body shape and culinary use.
The origin is uncertain, but it is a native Japanese word. The kanji 蟹 is a Chinese character adopted for its meaning.