Stephen Matheson has a series of posts about introns and their misuse by the Disco 'Tute.
Genes are transcribed into RNA for shipping out of the nucleus to make proteins. Introns are areas of the RNA that have been transcribed from the gene but are then removed from the RNA template prior to it moving out of the nucleus.
It all about the junk - or not-junk.
Go read Steve's posts Part I, Part II, and Part III, and get informed.