Capital is another word for resources. The capital of a business are the sum of the resources available to the business for any of their expenses. It can also be a measure of the value of the company.
Cash, financial assets, hard assets, stock, preferred stock, natural resources, equipment, value of contracts and others.
Working capital is a reference to the resources that the company uses in everyday business. The cash, receivables and other liquid assets the company is using in order to do business. For many companies, their working capital is borrowed on short term loans from banks.