I understand M-C-M’ as basically how capitalists use the money they already have to make even more money. The first M is the money they start with. They use that money to buy C, which can include things like machines, materials, buildings, and labor power. Then those things are used to make products that can be sold. The last M’ is the money they end up with, and it should be more than what they started with. The reading explains that the difference between M and M’ is the profit, or surplus value. To me, this is how capitalists keep building their wealth: they don’t just make money and stop there. They put that money back into the process so they can buy more, produce more, and sell more. The reading says they can keep putting their money back into circulation, which allows their capital to keep growing. Labor is a big part of this too because workers help create the new value in the products being made. So basically, the capitalist starts with money, uses it to produce something, sells it for more money, and then repeats the process.