Organically grown grains are farmed without using pesticides, insecticides, or commercially produced fertilizers, etc. The soil they are grown in has been set aside (or has not had pesticides, etc. used) for a certain period of time (generally 3 years). The processing of the grains also cannot utilize any outside chemicals, etc. to get the end resulting product.
In the US, federal organic legislation defines three levels of organics. Products made entirely with certified organic ingredients and methods can be labeled "100% organic". Products with at least 95% organic ingredients can use the word "organic". Both of these categories may also display the USDA organic seal. A third category, containing a minimum of 70% organic ingredients, can be labeled "made with organic ingredients". In addition, products may also display the logo of the certification body that approved them. Products made with less than 70% organic ingredients cannot advertise this information to consumers and can only mention this fact in the product's ingredient statement.