On a balance sheet, the assets of a business are generally broken down into two groups: current assets and fixed assets.
Current assets are generally considered to be anything that will be converted into cash within one year, such as cash, accounts receivable, and inventory. Current assets continually turn over through the company.
Fixed assets are more permanent in nature. This includes vehicles, equipment, machinery, land, and buildings. They represent an investment in items that are necessary to carry on its normal operations. Fixed assets can also revolve (to purchase new equipment or update technology, for example) but usually they revolve very slowly.
Liquidity measures how quickly a company can convert its assets into cash. An ample cash balance provides security that the company can meet its obligations. The easier the conversion is, the more liquid the asset. Here is a list of current assets in order from most to least liquid: