Firstly, we shall understand what a capital is.
Capital is Money needed to start and run the business. Companies need capital amount for its preliminary expenses and infrastructure setup of the business. Also they need working capital to run the business consistently. In simple terms, Money needed to setup and run the business is called capital.
Capital requirement can be of long term or short term. Let us assume, if a company is going to invest in a huge plant with advanced machineries, they need lot of capital to invest in that for long term. Sometimes the companies need funds in short term for a quick project.
The financial institutions and investors who help companies in raising long term capital are collectively called as capital market. It can be a Bank, stock market or financing companies who provide long term capital
The financial setup which provides short term capital or working capital to companies is called Money market. Bond, debentures like financial instruments which matures normally within a year are called money market instruments.