Viviparous: Organisms that give birth to young ones
Number of offsprings are small
Have multiple reproductive cycles
All mammals, certain plant species (Rhizophora)
Oviparous: organisms that lay eggs
Number of offsprings can be many (insects, molluscs and crustaceans) or few.
some organisms may have a single reproductive cycle (certain insects, molluscs and crustaceans ) while fishes, amphibians, birds and reptiles have multiple reproductive cycle.