Whaling is the practice of hunting whales, big animals that live in the ocean. People have been hunting whales for thousands of years, mostly for their meat and oil. In the past, whales were very important to people because their oil was used to make candles, lamps, soap and other things.
Whaling used to be a very dangerous job. It was done on small boats and hunters used harpoons to kill the whales from close distance. Over time, better technology was developed, like bigger boats and guns, which made whaling easier and safer.
In the 16th century, whaling became a big industry and it spread all over the world. People were hunting whales for a lot of different reasons. Some did it for the meat and oil, others for the bones and baleen (the hair-like structures in the mouth of some whales). Many countries, like America and Japan, even built their own whaling fleets and sent them out to hunt.
However, in the 20th century, people started to realize that hunting whales was causing big problems. Many whale populations were becoming small and there was a risk that some types of whale could become extinct. In the 1960s, an international agreement was signed by many countries to stop commercial whaling, which means hunting whales for money.
Nowadays, people still hunt whales, but in much smaller amounts and it's mainly for scientific or cultural purposes. Some countries, like Japan, still have a whaling industry, but many people are against it and think that whales should be left alone in the wild.