Working Capital generally refers to the firm's system of assets and liabilities in their current status. Current assets include cash and all the assets that can be converted to cash within 1 year. These assets are the marketable securities, accounts receivable, and inventory. Current liabilities are all the obligations that have to be paid within a year such as the accounts payable, fixed payments that include rent and lease payments, utilities due, and insurance premiums, as well as the accrued payments of payroll and taxes, in addition to the due payments on any long-term debt.
Working capital (WC) concept could be used in terms of being gross and net. Gross working capital (GWC) is just another name for the current assets (CA), while net working capital (NWC) is the difference between current assets and current liabilities.
In this sense, the NWC is an analogous concept to the net worth on an individual level. It would indicate what the firm owns versus what it owes, all in a current timing. In other words, it would make a measure of the firm's liquidity and its ability to pay for its present obligations, and in that, it could be understood as the relationship between the firm's current outflows and inflows.