apologies for asking a stupid question,but i have been wondering about this.is it basically earth (like middle earth in tolkien's books).or is it a completely different planet altogether.also how many continents are yet to be seen (but are written about maybe in books in the game).would be interested to hear your views

Its not a stupid question friend. The world in which Tamriel and the other continents are on is called Nirn and it's a completely different world than Earth. There are four continents that we know exist. Yokuda, Tamriel, Akivir and Atmora and we've only seen Tamriel.

Edit: I forgot to mention Pyandonea.

TES takes place on Nirn, a planet which has nothing to do with earth.

Continents:
Tamriel
Atmora
Yokuda
Akavir

Size uncertain:
Pyandonea

Important note: Ignore the talos-priest ranting about in whiterun about the "earth". It's Nirn.

The planet is called 'Nirn', and it's not really Earth- more like it exists in another reality entirely. The continent in which the game is set is called 'Tamriel'. Other continents, which have not been visited, include 'Yokuda', which is where the redguards came from, and which was kind of destroyed; 'Atmora', where the Nords came from, which froze over; and 'Akavir', which is inhabited by vampire snakes and a tiger dragon, among other things.

[edit] Ninja'd. Multiple times. The shame.

thanks for the replies. the world is a lot bigger than i had already envisaged and it was already huge to begin with edit that tiger dragon sounds very interesting