In finance and investing terms, capital is just another word for assets. These can be funds that you have in a deposit account, a companys assets, or even physical assets such as property. There are different types of capital (working, equity, and debt) in business, but in general terms, it refers to financial assets.
Example: If youre starting certain businesses from scratch and you need to form a capital structure, youll choose from different types of capital, such as debt, equity, or working capital. If you take out a loan and acquire debt, youll have debt capital. This means that the business has the capital (financial assets, in this case, cash) to grow and acquire more capital, but its debt capital, meaning that youll have to pay it back.