White tigers are not a naturally occurring species. They are a captive bred abnormality.
White tigers are distinct for the normal coloration in that they lack the Pheomelanin pigment that in normal tigers produces the orange colour. They still produce the pigment, eumelanin, and hence are not considered albino. Compared to normal tigers without the white gene, white tigers tend to be somewhat bigger, both at birth and as fully grown adults.
We keep them at Paradise Wildlife Park for educational purposes and as ambassadors for their species.