Question

What would happen if two different species mated?

Answer 1

In biology, mating is the pairing, usually for the use of sexual propagation, of opposite sex or hermaphrodism organisms. Some definitions limit the term to contrasting animals, while others extend the terminology to pairing plants and fungi. The merger of two gametes is fertilisation.

Complete answer:
They are unable to do so technically.
What allows us to distinguish two species is also what prevents them from successfully mating, their hereditary characteristics. When two individuals of the same species mate, the haploid cells (egg and sperm) combine to form a full diploid cell with all of the chromosomes. In the case of humans, a full set consists of 23 sets or 46 individual chromosomes.
However, when two individuals from different species mate, their hereditary data is contradictory. The number of chromosomes, among other things, prevents practical posterity from occurring most of the time. A successful cross-species breeding would be the combination of a Tiger and a Lion, which is a useful animal that has previously been created. Regardless, it is hereditarily incapable of having offspring of its own, which is why they do not spread.
This appears irrational in light of the vast number of species on Earth, but consider it as such. When two people of a similar species become diverse enough that they can no longer reproduce effectively, they are considered different species, and their phylogenetic trees will most likely never blend again.
A cat and a dog cannot give future generations at the same time. They are incredibly hereditarily distinct, and their chromosomes do not coordinate correctly or in the correct numbers.
In some cases, two distinct species will have coordinating chromosome tallies, or are sufficiently close to raise, despite the fact that they aren't all that closely related. This is an extraordinary occurrence, but it has occurred. Corn snakes and kingsnakes have hybridised, resulting in ripe and solid offspring. This is important because they aren't just different species; they're different Genera.

Note:
Similarly, regular are closely related species that can hybridise, but their offspring are sterile, or only one sex is sterile. Alternatively, having a few genes for development or different characteristics that do not work effectively. (Ligers, for example, can grow to be larger than one or both tigers or lions - the most massive enormous feline on the planet.) Donkeys are normally sterile, as are male ligers; however, females are prolific (and can deliver posterity with either parent species - making li - ligers or ti-ligers).