Natural--Just because Cotton is natural does not mean it is organic.  Cotton itself is a natural fiber,  it is grown and harvested.  But conventional cotton is very different from Organic Cotton.

Green- In the U.S. 'green' cotton usually refers to cotton that is not bleached, dyed or chemically treated during processing.  However, it is grown conventionally, and falls short of organic.  Unlike the use of the word 'organic' in labeling, neither of these terms are regulated or certified, so they may not always have a consistent meaning.

Organic cotton is grown using methods and materials that have a low impact on the environment. A field must be pesticide-free for at least three years to be certified organic.  The cotton must then be processed according to international organic standards.  Organic production systems replenish and maintain soil fertility, reduce the use of toxic and persistent pesticides and fertilizers, and build biologically diverse agriculture.

In the U.S., cotton labeled as organic has to go through Third-party certification organizations which verify that organic producers use only methods and materials allowed in organic production.
People with allergies and chemical sensitivity will especially benefit from organic cotton clothing, as conventional cotton may retain harmful toxic residues. Even if you don't have sensitive skin, organic cotton will just feel better against your skin.

How cotton is raised and processed can have a direct impact on health and safety. Organic cotton provides all the benefits and comfort we've grown to love throughout our lives, without the chemicals.