hi everyone,
I would like to buy wifi shield but I am really confused what are the differences between these two:
Those two boards look like the same board to me - only difference is camera angle, and one has a piece of angled pin header pushed into the FTDI header.
what about the configuration and firmware upgrade? is it the same or not?
Arduino.cc has discontinued that board and is now offering the WiFi 101 board through their USA Web site to purchasers in the USA. The WiFi 101 board performs better and has a lower price, however it doesn't have the SD slot. Mine came without the need for firmware upgrade. I don't know when the WiFi 101 will be available worldwide but they will likely bear the Genuino trademark due to an outstanding trademark dispute.
A minor issue with the WiFi 101 is that its library support is only for the Arduino.cc Zero board. It should work fine with the AVR-based boards, but you may have to deal with library issues until it is certified for the other Arduino boards. I don't consider this an issue because the Zero board has greater memory and faster processing, things that I like in applications that use WiFi.
Your boards aa and bb are either old stock, counterfeit boards, or products of another company. The pictures you are showing are likely from dealers on the internet and the board you get may be any of these, you won't be able to know for sure until you examine the artwork on the back. You will most likely have to upgrade the firmware, but that's an easy step. If your dealer is reputable he will stand behind the product and it will probably work fine for you.
The gender of the FTDI connector should be of no consequence because you most likely won't ever need to use that interface.
Surfing Dude has pretty much explained everything for OP. Can I ASK OP about the project you are considering with arduino WiFi. Maybe a digi xbee-wifi module is better suited. I've used the arduino wifi shield extensively and have many complaints, besides it being expensive. If you describe your project, we can better guide you with your purchase.