In a companys balance sheet, long-term capital is the same as the companys long-term liabilities plus equity capital.
Long-term is used to define transactions that takes more than a year to settle.
Long-term liabilities has been used to invest in long-term assets, which in turn can be converted into cash if needed.
Equity capital can consist of both cash and shares held by the investors in the company.
Reference: Oxford Press Dictonary of Economics, 5th edt.