For stock investors that favor companies with good fundamentals, a "strong" balance sheet is an important consideration for investing in a company's stock. The strength of a company's balance sheet can be evaluated by three broad categories of investment-quality measurements: working capital adequacy; asset performance; and capital structure. In this article, we'll look at evaluating balance sheet strength based on the composition of a company's capital structure.
A company's capitalization (not to be confused with market capitalization) describes the composition of a company's permanent or long-term capital, which consists of a combination of debt and equity. A healthy proportion of equity capital, as opposed to debt capital, in a company's capital structure is an indication of financial fitness.
Clarifying Capital Structure Related Terminology
The equity part of the debt-equity relationship is the easiest to define. In a company's capital structure, equity consists of a company's common and preferred stock plus retained earnings, which are summed up in the shareholders' equity account on a balance sheet. This invested capital and debt, generally of the long-term variety, comprises a company's capitalization, i.e. a permanent type of funding to support a company's growth and related assets.
Source : Investopedia