LEED, or Leadership in Energy and Environmental Design, is an internationally-recognized green building certification system. Developed by the U.S. Green Building Council (USGBC) in March 2000, LEED provides building owners and operators with a framework for identifying and implementing practical and measurable green building design, construction, operations and maintenance solutions. LEED promotes sustainable building and development practices through a suite of rating systems that recognize projects that implement strategies for better environmental and health performance.

Key elements of the process include a balanced and transparent committee structure, technical advisory groups that ensure scientific consistency and rigor, opportunities for stakeholder comment and review, member ballot of new rating systems, and fair and open appeals.

LEED certification provides independent, third-party verification that a building or community was designed and built using strategies aimed at achieving high performance in five key areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.

There are both environmental and financial benefits to earning LEED certification. LEED-certified buildings are designed to:

• Lower operating costs and increase asset value
• Reduce waste sent to landfills
• Conserve energy and water
• Be healthier and safer for occupants
• Reduce harmful greenhouse gas emissions
• Qualify for tax rebates, zoning allowances and other incentives in hundreds of cities

Source - http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1990
Source - http://www.usgbc.org/DisplayPage.aspx?CMSPageID=1988