For example, if an investor in a 25% tax bracket had $10,000 in long-term capital gains, there would be a tax liability of $1,500. If the same investor sold underperforming investments carrying $10,000 in long-term capital losses, the losses would offset the gains, resulting in a tax liability of 0. If the same losing investment were brought back, then a minimum of 30 days would have to pass to avoid incurring a wash sale. 
Accounting is one of the key functions for almost any business. It may be handled by a bookkeeper or an accountant at a small firm, or by sizable finance departments with dozens of employees at larger companies. The reports generated by various streams of accounting, such as cost accounting and managerial accounting, are invaluable in helping management make informed business decisions.