These classifications are used to differentiate flowers:
Annuals are usually the showiest flowers that last for one very productive season We often buy them for seasonal bedding plants ie. pansies, snapgragons, marigolds, and petunias. Some of these will drop seeds that sprout the following year, but the plant itself does not regenerate.
Biennials have one season of growth, a second year of bloom ie. some foxglove and delphiniums. These are best planted in rotations for constant production.
Perennials will live a few to many years, repeating their life cycles over and over. Periods of actual bloom may still be for a short time each season. These include penstemon, salvias, fuschias coreopsis, geraniums, chrysanthemums, etc.
Trees and shrubs, and bulbs fall into their own categories