What is the difference between lime and calamansi?

They look similar to green lemons but its sweet unlike lemons

This one time i did not see the difference and i just had it since i love lemons you see and then boom i was like since when is lemon sweet then someone told me this is calamansi

Calamansi is sour and tends to be smaller than lime. Calamansi is a cross between kumquat and citrus. The peel of calamansi is sweet as compared to that of lime. For cooking purposes, you can use either, however, calamansi proves to be an excellent garnishing ingredient for drinks, and you can also use its peel to make marmalade.