breeding is a process of concentrating certain traits to enhance their presence in the offspring of crossing them. A plant will exhibit a phenotype (what it looks like, feels like, smell like, smokes like etc.....whatever trait you want to use to physically describe it). that phenotype is an expression of the genotype (the genetic map that together with environmental factors - dictates the pheno). say for example you have two people that each have short legs and long bodies. its unlikely that a child will have short legs and a long body from that cross. not that it would not happen, but unlikely. sometimes certain traits are also generational...meaning they may only express themselves fully every second or even third generation.
So you take individual plants that exhibit certain traits (blueberry smell + taste) and cross with others of similar traits or complementarty traits to further enhance the trait you wish your strain to emphasize.
