Certification...

To ISO management system standards
Organizations and companies often want to get certified to ISO’s management system standards (for example ISO 9001 or ISO 14001) although certification is not a requirement. The best reason for wanting to implement these standards is to improve the efficiency and effectiveness of company operations.
A company may decide to seek certification for many reasons, as certification may:
be a contractual or regulatory requirement be necessary to meet customer preferences
fall within the context of a risk management programme, and
help motivate staff by setting a clear goal for the development of its management system.

ISO 9000 - Quality management

The ISO 9000 family addresses various aspects of quality management and contains some of ISO’s best known standards. The standards provide guidance and tools for companies and organizations who want to ensure that their products and services consistently meet customer’s requirements, and that quality is consistently improved.

ISO 9001:2008

ISO 9001:2008 sets out the criteria for a quality management system and is the only standard in the family that can be certified to (although this is not a requirement). It can be used by any organization, large or small, regardless of its field of activity. In fact ISO 9001:2008 is implemented by over one million companies and organizations in over 170 countries.

Quality Management Principles: The standard is based on a number of quality management principles including a strong customer focus, the motivation and implication of top management, the process approach and continual improvement. These principles are explained in more detail in the pdf Quality Management Principles. Using ISO 9001:2008 helps ensure that customers get consistent, good quality products and services, which in turn brings many business benefits.

Audits: Checking that the system works is a vital part of ISO 9001:2008. An organization must perform internal audits to check how its quality management system is working. An organization may decide to invite an independent certification body to verify that it is in conformity to the standard, but there is no requirement for this. Alternatively, it might invite its clients to audit the quality system for themselves. Read more about certification to management system standards.

ISO 14000 - Environmental management

The ISO 14000 family addresses various aspects of environmental management. It provides practical tools for companies and organizations looking to identify and control their environmental impact and constantly improve their environmental performance. ISO 14001:2004 and ISO 14004:2004 focus on environmental management systems. The other standards in the family focus on specific environmental aspects such as life cycle analysis, communication and auditing.

ISO 14001:2004 sets out the criteria for an environmental management system and can be certified to. It does not state requirements for environmental performance, but maps out a framework that a company or organization can follow to set up an effective environmental management system. It can be used by any organization regardless of its activity or sector. Using ISO 14001:2004 can provide assurance to company management and employees as well as external stakeholders that environmental impact is being measured and improved.

The benefits of using ISO 14001:2004 can include:

Reduced cost of waste management
Savings in consumption of energy and materials
Lower distribution costs
Improved corporate image among regulators, customers and the public

Source: http://www.iso.org/iso/home.html