The Felidae

Felidae is the generic term for all big and small cats. It is a subdivision of the mammals. Therefore in biological terms, 'Felidae' is the name of the family of the tiger. A family contains several species with a number of common characteristics.

The felidae are often subdivided into two other subfamilies: the big cats (Pantherinae) and the small cats (Felinae).

Between the big and the small cats there are, except for their dimensions, several other differences. The more important onces are:

Big cats:

can roar.
→ They possess a soft lingual bone (Hyoid bone), which enables roaring.
can only purr while exhaling.
eat their bigger prey while lying down.
have round pupils.

Small cats:

can not roar.
can purr continuously.
eat their bigger prey in a crouch.
have slit pupils.

The Pantherinae

The Pantherinae, the subfamily of the big cats, can be subdivided again in some (biological) genera. Two members of the same genus have even more characteristics in common than two members of the same family.
The big cats exist out of 3 different genera:

Genus Panthera
Exists of the tiger (Panthera tigris), the lion (Panthera leo), the leopard (Panthera pardus) and the Jaguar (Panthera onca).
Genus Neofelis
Exists of the Clouded Leopard (Neofelis nebulosa) and the Bornean Clouded Leopard (Neofelis diardi).
Genus Uncia
Exists of the Snow Leopard (Uncia uncia).

Relevant links:

The Felidae

The Felidae

The Pantherinae