What are the differences between Heirloom, Organic, Pelleted & GMO seeds?

Heirloom seeds are seeds that that have been cultivated from healthy non-modified plants.  Some heirloom seeds can trace their ancestory back over 100 years.  That does not mean the seeds are old, just that we know where they come from

Organic seeds are derived from a method of growing plants through enough generations to predominately eliminate the effects of growing in a non-organic method. 

Pelleted seeds are seeds (usually the smaller seeds that are hard to handle) that are encased in a fairly uniform ball of clay.  This makes handling them much easier, saving time.  The time savings may not mean much to the backyard gardener planting 50 seeds, but to the commercial grower planting by the thousands, the time savings is significant. 

GMO seeds are seeds that have been genetically modified.  While it sounds innocent enough, personally we want absolutely nothing to do with GMO seeds.  In creating GMO seeds, they will try to isolate the genetics of one specie with a desired trait and inject it into the seed's genetics.  Take for an example, a trait of a spider and inject it into corn seeds.  Google GMO seeds and you will get plenty of information from both sides.  Sadly our politicians have passed laws saying companies like Monsanto, who processes GMO seeds cannot be sued if the GMO products prove unhealthy.  These laws were passed prior to knowing any long term negative effects of these products.  We do not have enough GMO data to verify the safety of GMO products.   Additionally many areas do not require GMO foods to be labled as such, so many are consuming GMO products are unaware of it.  Such are the tactics of big business.