Tablets: Intuos4 other type of Pen and Nibs ?

[ashphotoart]

While I was seraching for the Intuos 4 Pen Tablet I come with some interesting questions. here what supply in the box with Intuos4.
1. Wacom Intuos4 Digital Tablet (Medium)
2. Mouse
3. Grip Pen
4. Pen Stand
5. 5 x Standard Nibs
6. Flex Nib
7. Stroke Nib
8. 3 x Hard Felt Nibs
9. Nib Extractor
10. 8.2' (2.5 m) USB Cable
11. Quick Start Guide
12. Installation CD with Driver Software and Electronic User Manual
13. 2-Year Limited Warranty


when I searched for accessories I found variety of Pens and Variety of Nibs.
please clear me what to use for what Purpose ?
Variety of Pens :-
1. Art Pen
2. Classic Pen
3. Grip Pen (comes with tablet)
4. Inking Pen

Variety of Nibs :-
1. Chisel Felt Nibs 5 pack
2. Flex Nibs
3. Hard Felt Nibs
4. Standard nibs black 5 pack
5. Stroke Nibs for use w intuou4


I'm trying to attach the photos of the Pens and Nibs.

[ashphotoart]

attached snapshots and link

http://www.bhphotovideo.com/c/search...tuos4+nibs&N=0