It is a test required for a Master degree (especially from schools in the US, CANADA and EUROPE)
The analytical Writing tests measure your critical thinking and analytical writing skills.
The GRE verbal section places premium on vocabulary. Learning words in context gives you a better shot at acing the GRE than merely rote-learning the definition of words.
This is the MATH section of the GRE. Unlike the GMAT where no calculator is either provided or allowed, an on-screen calculator is available for use in the GRE.