Hello.
nRF24L01 is not a WiFi module. WiFi is established as a communication protocol that uses 2,4GHz band to send data between devices. This IC (or take it as a module) is a 2,4GHz transceiver that casually uses the same band that WiFi does.
I have used it, it's pretty simple to achieve a simple communication, but it has very specific functions that you can use in more professional applications such as sending the same packet of data several times (you can set how many) if it doesn't get an acknowledge message, interrupts, three FIFO payloads, upto 6 pipes per channel, and low power modes.
What I like from it is that you don't have to buy two modules by separate for Tx/Rx, you just change it's operation mode when you send data and get it back to Rx... If I am not wrong, if you put something in the TX payload, it automatically puts in TX mode, sends it, and then gets back to Rx.
IMPORTANT NOTICE: I used the same module you hold, and its range its not the best.. it had to reach 50m or so, in free air, but you have to take into account the orientation of the antenna as it's not symmethrical. At maximum power it will draw less than 14mA, which is pretty good.
UNfortunately I don't have a code for arduino, but what I wanted you to know is that you won't be able to communicate it with a WiFi server, but you could communicate several of them using the pipes feature.