| Packet | Packet Filter |
| Packet Filtering | Parallel Port |
| Password | Peer-to-Peer |
| Peripheral Component Interconnect | Petabyte |
| Phreaker | PING |
| PLZ | POP3 Server |
| Porn Dialers | Port |
| Portable Document Format | POST |
| Post Office Protocol 3 | Power Supply Unit |
| Program | Protocol |
| Proxy Server | Pubstro |
