| PCI | Payment Card Industry |
| PCIe | Peripheral Component Interconnect Express |
| PCIX | Peripheral Component Interconnect Extended |
| PCL | Printer Command Language |
| PCMCIA | Personal Computer Memory Card International Association |
| PE | Preinstallation Environment |
| PGA | Pin Grid Array |
| PGA2 | Pin Grid Array 2 |
| PGP | Pretty Good Protection |
| PII | Personally Identifiable Information |
| PIN | Personal Identification Number |
| PHI | Personal Health Information |
| PKI | Public Key Infrastructure |
| PnP | Plug and Play |
| PoE | Power over Ethernet |
| POP3 | Post Office Protocol 3 |
| PoS | Point of Sale |
| POST | Power-On Self-Test |
| POTS | Plain Old Telephone Service |
| PPM | Pages Per Minute |
| PPP | Point-to-Point Protocol |
| PPTP | Point-to-Point Tunneling Protocol |
| PRI | Primary Rate Interface |
| PROM | Programmable Read-Only Memory |
| PS/2 | Personal System/2 connector |
| PSTN | Public Switched Telephone Network |
| PSU | Power Supply Unit |
| PVA | Patterned Vertical Alignment |
| PVC | Permanent Virtual Circuit |
| PXE | Preboot Execution Environment |
| QoS | Quality of Service |
| RADIUS | Remote Authentication Dial-In User Server |
| RAID | Redundant Array of Independent (or Inexpensive) Disks |
| RAM | Random Access Memory |
| RAS | Remote Access Service |
| RDP | Remote Desktop Protocol |
| RF | Radio Frequency |
| RFI | Radio Frequency Interference |
| RFID | Radio Frequency Identification |
| RGB | Red Green Blue |
| RIP | Routing Information Protocol |
| RIS | Remote Installation Service |
| RISC | Reduced Instruction Set Computer |
| RJ-11 | Registered Jack Function 11 |
| RJ-45 | Registered Jack Function 45 |
| RMA | Returned Materials Authorization |
| ROM | Read-Only Memory |
| RPO | Recovery Point Objective |
| RTC | Real-Time Clock |
| RT | Recovery Time Objective |
| Saas | Software as a Service |
| SAN | Storage Area Network |
| SAS | Serial Attached SCSI |
| SATA | Serial Advanced Technology Attachment |
| SC | Subscription Channel |
| SCP | Secure Copy Protection |
| SCSI | Small Computer System Interface |
| SCSI | ID Small Computer System Interface Identifier |
| SD card | Secure Digital Card |
| SEC | Single Edge Connector |
| SFC | System File Checker |
| SFF | Small Form Factor |
| SFTP | Secure File Transfer Protocol |
| SIM | Subscriber Identity Module |
| SIMM | Single In-Line Memory Module |
| SLI | Scalable Link Interface or System Level Integration or Scanline Interleave Mode |
| S.M.A.R.T. | Self-Monitoring, Analysis, and Reporting Technology |
| SMB | Server Message Block |
| SMTP | Simple Mail Transfer Protocol |
| SNMP | Simple Network Management Protocol |
| SoDIMM | Small Outline Dual Inline Memory Module |
| SOHO | Small Office/Home Office |
| SP | Service Pack |
| SPDIF | Sony-Philips Digital Interface Format |
| SPGA | Staggered Pin Grid Array |
| SRAM | Static Random Access Memory |
| SSD | Solid State Drive |
| SSH | Secure Shell |
| SSID | Service Set Identifier |
| SSL | Secure Sockets Layer |
| SSO | Single Sign-on |
| ST | Straight Tip |
| STP | Shielded Twisted Pair |
| SXGA | Super Extended Graphics Array |
| TACACS | Terminal Access Controller Access-Control System |
| TCP | Transmission Control Protocol |
| TCP/IP | Transmission Control Protocol/Internet Protocol |
| TDR | Time Domain Reflectometer |
| TFTP | Trivial File Transfer Protocol |
| TKIP | Temporal Key Integrity Protocol |
| TLS | Transport Layer Security |
| TN | Twisted Nematic |
| TPM | Trusted Platform Module |
| UAC | User Account Control |
| UDF | User Defined Functions or Universal Disk Format or Universal Data Format |
| UDP | User Datagram Protocol |
| UEFI | Unified Extensible Firmware Interface |
| UNC | Universal Naming Convention |
| UPnP | Universal Plug and Play |
| UPS | Uninterruptible Power Supply |
