Easier - A gold rush happens when people hear that gold has been found. They then rush to seek their fortune.
Gold is a soft, yellow precious metal that is very valuable.
Some people use gold as money. The California Gold Rush is very famous. Thousands of people moved to California after gold was found by James Marshall at Sutter's Mill on January 24, 1848. Most miners used a shallow pan to find flakes of gold in streams. Although there have been many gold rushes, the California Gold Rush brought over 200,000 new people to California in just a few years.