What is organic?

That depends.  On order to be labeled organic, a products, its producer, and the farmer must: 1.) meet the USDA's organic standards and 2.) must be certified by a USDA approved certifying agency.  Organic foods cannot be grown using synthetic fertilizers, chemicals, or sewer sludge; cannot be genetically modified and cannot be irradiated.

Organic meat and poultry must be fed only organically- grown feed (without any animal by-products (and cannot be treated with hormones or antibiotics.  Furthermore, the animals must have access to the outdoors and have access to pasture (Note:  this does not mean the animals actually have to outdoors and graze to be considered organic).

Variations of the term organic exist because the USDA does not itself provide organic certification but, instead,  accredits state, private, and foreign organizations, groups, or persons to become "certifying agents".