With breeding there are breeding strains, F1, F3, 4.5.6..etc.. A breeding strain is a stabilized strain that only has one phenotype in the plant. And F1 is a cross between two strains. an F2 is a cross between an F1 and an F1.
If you didnt understand that here is an easier version. an F1 is W x X, an F2 is taking the W crossed with the X male or female and crossing it with another F1 of a different strain. F1's are hybrids and breeding strains are like sour diesel.
If you take a breeding strain and cross it with an F1 you get another breeding strain. It is really tricky and can be understood better if you just googled F1 vs F2 seeds.
F2 seeds are not less quality than F1 seeds they just have say 4 phenotypes, but F1 strains have 2 phenotypes and breeding strains have 1 phenotype.
What the poster above you created by crossing Skywalker with Northern Lights would be all F2 seeds. Hope this helps.