Everything we eat, drink, or wear was produced. Everything that keeps us alive and comfortable had to be made or brought to us by somebody, and that somebody had to have tools to do it with.
Our remote ancestors lived in primitive economies, in which things were there or not according to chance or the intervention of Deity; our later ancestors lived in agricultural economies, in which food and fiber were produced, but much else was either encountered by chance or self-work. We live in an industrial economy, in which the things we need to live are not available to us directly, either because they’re too far away or because their natural form isn’t useful to us; production turns those unavailable or un-useful things into things that are useful and available.
Production requires tools. Marx called the tools “means of production”, both as a perfectly valid generalization and because he was uncomfortable with the inegalitarian implications. “Tools” is easier to type, and almost as general.
Tools have to be made. A simple tool like a hammer can’t exist unless somebody digs up iron ore, smelts it into iron, forms it into the head, cuts down a tree and shapes it into a handle, and assembles the parts. A factory can’t exist unless somebody collects all the materials and shapes it into a building and the machines inside. This is the basic characteristic of an industrial economy: the tools, the means of production, must themselves be produced.
Production also requires materials — either raw materials, like the iron ore that made the hammer head, or materials that are themselves produced, like the bricks that make up a factory building. Those materials can’t be used for something else at the same time. The iron ore can’t be used to make a frying pan, because it went into the hammer instead; the bricks can’t be used to build somebody a house, because they’re part of the factory; the labor that made the hammer or built the factory couldn’t be used to grow crops, because then there would be no hammer or factory.
You can’t take the materials out and use them for something else, either. If you take away the iron from the hammer and use it to make a frying pan, there’s no hammer any more. If you take the bricks out of the factory to build a house, the factory falls down — and its production is no longer available. The materials and labor used to produce the tools are a permanent part of the tools. If you take them away, you don’t have the tools any more, and you don’t have the production that the tools enable.
Frustrating, isn’t it? You can see the wealth — the materials — right in front of you, and you can’t do anything else with them. The hammer is a little bit of wealth, and if you take it there’s no hammer. The factory is a big pile of wealth, and if you take it there’s no factory any more. That’s why there’s a special name for the wealth that is “frozen” into tools, into the means of production, and that name is capital.
It doesn’t really matter who “owns” the capital. Whether it’s a private individual (who is “rich”), “the People”, or Government (usually in the name of the People), the assets — the wealth, the materials — that go into the tools are permanently embodied in the tools, and can’t be used for anything else without losing the production the tools enable. If you do away with capital, you do away with the means of production; without the means there is no production, and without production we all die, because all the things that keep us alive are produced.