Capital

Money set aside to be put to work, as opposed to money earmarked for near-term spending.

Example

The $10,000 you invest is capital; the $10,000 in your checking account for next month's rent is not.

Investing money you will need within the next year or two turns an ordinary market dip into a forced, permanent loss.

Investing — Committing money today with the expectation of more money later, in exchange for taking on risk and giving up the ability to spend that money now.
Risk tolerance — How much decline in the value of your investments you can withstand financially and emotionally without abandoning your plan.
Emergency fund — Cash set aside, outside of any investment, to cover unplanned expenses or lost income.

What investing actually is — Investing is putting money at risk today in exchange for more of it later. Everything else in this Academy is detail on top of that one trade. (9 min)
Buying a small business almost always means buying a job — A small-business purchase is rarely a passive claim on cash flow. Most of what you are paying for is bound up with the seller's own labour, and the legal structure of the deal decides which liabilities move with it. (9 min)