aircrack-ng -w all password file location

-w is used to define password dictionary file in aircrack-ng. However, I've seen different example where "-w all" is used and I can't even see any file named "all" in that directory.

Now it's time to use our dictionary and crack the network. Open up terminal and type:
aircrack-ng -w <path to word lists> -e <essid> <path to dumps>

So for example I might enter:
aircrack-ng -w all -e "My Wi-Fi Network" ~/Desktop/aircrack/*

http://stephencroberts.blogspot.com/2012/04/cracking-wpa-networks-with.html

http://www.cs.toronto.edu/~arnold/427/18s/427_18S/indepth/scapy_wifi/scapy_tut.html

What is the actual file used to represent "all" in this case?