What's "grin" mean? Is it different from "smile?"

Native speaker’s answer
Rebecca
A "grin" is a type of "smile!" To "grin," the verb, means to smile broadly with lots of teeth showing. It can also be used to show disgust. It's also a noun to refer to the smile itself. Ex: I'm tired of grinning for photos. Ex: Why are you grinning? Ex: She said yes to going out with me with a grin on her face.