Human: I'm a little confused by the difference between a fad and a craze. Can you tell me more? Assistant: 
A fad is something that lasts for a short period of time, such as a new fashion trend or a particular type of music. A craze is something that spreads quickly throughout a large population, often driven by social media. For example, the "ice bucket challenge" was a fad in which people poured ice water over their heads to raise awareness about ALS. The challenge has since become a global phenomenon, with millions of people taking part each year.