Smileing is something physical As this other person said, the corners of your mouth point upwards, and many people smile when their picture is taken. Laughing is a sound that you make, and can be followed by physically smiling..you laugh when you see a funny movie or something.

Smile = both corners of your mouth point upwards, sometimes the teeth are seen as well. Most people smile when their picture is taken. Laugh = when people actually produce a 哈哈 sound, usually after someone tells a good joke or when you watch a comedy or something Of course, there's also a different kind of laughing. This is called 'laughing at someone'. For example, someone does something stupid and people laugh at him for being such an idiot.

The word "laugh" is not derogatory at all. However, to "laugh at" someone could be disrespectful.

smile withoud sound, laugh with sound. 晕，MM，没事儿灌水的吧？嘴唇闭拢，嘴巴往上翘就是smile, 嘴巴张开，喉咙里发出笑声，就是laugh