The capacity to reproduce and generate offspring is thought to be one of the fundamental aspects of all life.
Though, obviously, not every individual is capable of reproducing (for instance, non-reproductive castes of hive species), in theory at least some members of every species should. Even immortal species are likely to procreate at some point, even if it is extremely rare. Technologically advanced species often reproduce by artificial means, sometimes exclusively so.
Reproduction between two distinct species is comparatively rare, and results in hybrids.