Can anybody tell me what's the difference beetwen ...

If you look at the globe, you can see that the most northern place (the top) of the globe is the North Pole.  This is more north than Canada and Greenland, at the very top of the earth.  The South Pole is the complete opposite... it is at the very bottom (most south point) of the earth.  It is more south than Australia and is at the very bottom point of Antarctica. 

There's sea in the north pole and a land in the south pole.

There are some important differences :

The Antarctic is a land covered with  thick ice, and the Arctic is just an ice layer on the sea.

Antarctic has many mountains,  some of them reach the height of 3 km. and more.The Arctic is a flat area.

In antarctic the ice thickness reach 2.5 km.  In the arctic the thickness rarely achieve more than few meters.

90% of all the world ice are in Antarctic.

The Lowest temperature was detected in Antarctic =  -88.3 deg.(cel) in 1983.

In Antarctic there are a great quantity of valued minerals , like: Nickel, Gold, Silver, platinum, Iron....and more.   In the  Arctic you will not find, of course, any mineral.

In the arctic there is the north magnetic pole (at 78.18'' north, 104 west). Now it is moving 41 km/year to east.

There are  a difference in wildlife too: In the arctic you can meet the white bears (not in Antarctic), And in antarctic you can meet many species of penguins (but none of them in the arctic). 

Dont forget Santa lives only on the north pole