Liquidity ratios refer to a firm's ability to meet its immediate financial obligations in terms of cash on hand and assets that can be sold quickly, while solvency ratios compare a firm's total assets to its total obligations, even into the future. Both are measures of a firm's financial health.
When calculating a company's liquidity ratio, current assets are divided by current liabilities, with current liabilities being defined as the money a firm must pay within one year. Current assets don't include all of a firm's basic inventory, only such assets as marketable securities and the amount of money immediately owed by individuals or other firms. A bad indicator for the liquidity ratio is a high daily sales outstanding ratio, which indicates that the firm is taking too long to collect money it's owed.
Calculating solvency ratio is a bit simpler, in that it's a firm's total assets divided by its total liabilities. Total assets include all inventories. A lower solvency ratio indicates that a business is entering into a large amount of debt to continue its operations. If the ratio continues to lower, the firm may have its credit rating lowered, resulting in higher interest rates and a reduced ability to borrow money.