Clactonian is a name given to a very old and primitive way of making tools for hunting and gathering by our human ancestors. A long time ago, before people had fancy tools and machines, they had to find ways to make tools from materials they found in nature, like stones and sticks.
The Clactonian style of tool-making was used by our ancestors in the Lower Paleolithic period, which means it was around a very long time ago, before anyone today or our parents were born. The Clactonian people would take a big rock, and use another smaller, pointier rock to chip away at the edges of the big rock until it formed a sharp tool. They would use these tools for hunting animals, cutting fruits and gathering other resources.
These tools were not very sophisticated, but they were very important for survival in their time. Without these tools, the Clactonian people would not have been able to hunt or gather food as easily, which means they may not have survived as long.
Although this style of tool-making is no longer used today, it is interesting to learn about how people used to live a long, long time ago and how they made do with what they had.