What is a Low-Income Housing Tax Credit?

Its mentioned in the story below.

- The Wikipedia entry: 

The Low-Income Housing Tax Credit (LIHTC - often pronounced "lie-tech", Housing Credit) is a dollar-for-dollar tax credit in the United States for affordable housing investments. It was created under the Tax Reform Act of 1986 (TRA86) and gives incentives for the utilization of private equity in the development of affordable housing aimed at low-income Americans. LIHTC accounts for the majority (approximately 90%) of all affordable rental housing created in the United States today.[1] As the maximum rent that can be charged is based upon the Area Median Income ("AMI"), LIHTC housing remains unaffordable to many low-income (<30% AMI) renters. The credits are also commonly called Section 42 credits in reference to the applicable section of the Internal Revenue Code. The tax credits are more attractive than tax deductions as the credits provide a dollar-for-dollar reduction in a taxpayer's federal income tax, whereas a tax deduction only provides a reduction in taxable income. The "passive loss rules" and similar tax changes made by TRA86 greatly reduced the value of tax credits and deductions to individual taxpayers. Less than 10% of current credit expenditures are claimed by individual investors.