You go through each of these five stages during ever pentest you do.

1. Reconnaissance (active vs. passive)
   1. Active: Actually engage the target
   2. Passive: Googling, etc. (not directly against the target)
2. Scanning & Enumeration (Nmpa, Nessus, Nikto, etc.)
3. Exploitation (gaining access)
4. Maintaining Access
5. Covering Your Tracks (clean up what you did, create, broke, etc.)

Lather, rinse, repeat…