Early basalt choppers from Olduvai Gorge (Tanzania)
Chimpanzees use stones to hammer on nuts and break them open, and they collect stones to throw at enemies. So people have probably been using stones as tools and weapons since people first evolved, around two million years ago. But about 1.9 million years ago, long before modern people evolved with their big brains, and before people began to use fire, early people began to do something different: they began to shape the stones to make them more useful as tools.
Stone-knappers made these earliest chopper tools by hitting one stone against another, usually basalt but sometimes chert or flint. People used the choppers to cut meat off the bone, to crush bones to eat the marrow, and to cut wood and bone for other kinds of tools. People also used choppers to cut plants open to get at the soft parts inside.
Not too much later, about 1.5 million years ago, early people began to make more complicated stone tools. We call these Acheulean tools. Flint-knappers shaped Acheulean tools more carefully, so that they had long straight cutting edges, like a knife. People made these tools out of flint or obsidian. While people were still using these tools, about a million years ago, they invented cooking fires.
About 200,000 years ago, maybe about the time that early people evolved into modern humans, people also started to make new, better stone tools (but other early people like Neanderthals also made these same tools). We call these new tools Mousterian tools. To make Mousterian tools, you have to first shape the stone into a core, and then strike off the knife blades, so it takes two steps. The advantage is that Mousterian tools use less stone to make, and each tool can be resharpened so it will last longer. These were the tools that people took with them when they first left Africa about 60,000 years ago and started exploring Asia, Australia, and Europe.