i do not know why but i wish i was a tiger .)
They are gorgeous, graceful and     v ery powerful  ,  they are from the Panthera, genus, with the lion, leopard, jaguar, and snow leopard.. 
hmmm, I did not know they were all related
They're mostly apex predators, they prey on ungulates such as deer and bovids.
i am not sure what an ungulate means or apex
cows, goats, sheep, antelope, etc. They're the largest cat species .
bigger than lions? but I guess I have never seen both together to compare with
It means alpha predator, top of th e food chain. Their are six subspecies left, and they are endangered  says the IUCN
yeah that is sad they are dwindling in population
Asia and China. Today's tiger range is fragmented, stretching from Siberian temperate forests to subtropical and tropical forests on the Indian subcontinent and Sumatra. The tiger is listed as Endangered on the IUCN Red List since 1986. As of 2015, the global wild tiger population was estimated to number between 3,062 and 3,948 mature individuals, down from around 100,000 at the start of the 20th century, with most remaining populations occurring in small pockets isolated from each other. Major reasons for population decline include habitat destruction, habitat fragmentation and poaching
Big cat
The term "Big cat" is typically used to refer to any of the five living members of the genus "Panthera", namely tiger, lion, jaguar, leopard, and snow leopard.
Except the snow leopard, these species are able to roar.
A more liberal and expansive definition of the term includes species outside of "Panthera" including the cougar, clouded leopard, Sunda clouded leopard, cheetah and sometimes the several lynx species, although these added species also do not roar.