What does 'Red' indicate in the IUCN Red list (2004) ?

Define the IUCN Red list categories.

What is the purpose of IUCN Red list?

What is the number of extinct animals documented by the IUCN Red List( as per 2004 ) in the last 500 years ?

The word 'Red' in 'IUCN Red List' means

How many species are documented to be extinct in last 500 years by IUCN Red List, 2004?

How many species are documented to be extinct in last 500 years by IUCN Red List, 2004?

How many species are documented to be extinct in last 500 years by IUCN Red List, 2004?

What is the number of extinct species documented by the IUCN Red List( as per 2004 ) in the last 500 years ? 1)338 2)359 3)2000 4)784