A hybrid is a cross of two varieties of plants.  F1 depicts that it is a first generation of the hybrid plant.  Often an F1 Hybrid will not produce seed viable for planting or the plant produced by its seeds will have very low yields, so you may need to continue purchasing seeds should you wish to replant the same hybrid.  Hybrids are bred for disease resistance, heat or cold resistance or higher yield.  Check with your seed supplier as to the advantages of that particular hybrid.