Italian and flat-leaf parsley are the same thing. The name really depends on what markets you happen to be in. Parsley is native to southern Italy, so that's why some stores refer to it as 'Italian' parsley. The mildly flavored, flat-leafed version of this herb closely resembles cilantro in appearance, so be careful when shopping. Curly parsley leaves are... wait for it... curly. Besides differing in appearance, curly parsley has a stronger flavor than flat-leaf/Italian. It's assertive, robust, and forward.