Password is used as an authentication factor. There are 3 factors that can be used as authentication:
1. Something you know. This is your password (digits, string, pattern)
2. Something you have. This could be your access card or key.
3. Who you are. Biometrics such as your fingerprint, iris or face.

There are 2 types of password attacks:
1. Offline attack:
– rainbowcrack
– John The Ripper
– Crunch
2. Online attack:
– bruteSSH
– Hydra

There are also online cracking tools, such as: wireshark, hamster, tcpdump, etc.
Network spoofing tools is to perform meet in the middle(MITM) attack, tools: arpspoof, Ettercap, etc