What's The Difference Between Jalapenos And Green Chile Peppers

I have a recipe calls for chopped That green chile peppers.I Have Bought canned green chili peppers before.Buy am I suppose to buy 'em fresh and chop them up? "I Do not Think I Have Ever Seen Them In The fresh vegetable section of The Grocery store.Only jalapenos.Can INSTEAD I use 'em? What's the difference?