| A | B |
| SATA | Serial advanced technology attachment |
| SC | Subscription channel |
| SCSI | Small computer system interface |
| SCSI | ID small computer system interface identifier |
| SD | Secure digital card |
| SDRAM | Synchronous dynamic random access memory |
| SEC | Single edge connector |
| SFC | System file checker |
| SGRAM | Synchronous graphics random access memory |
| SIMM | Single inline memory module |
| SLI | Scalable link interface |
| SMB | Server message block or small to midsize business |
| SMTP | Simple mail transport protocol |
| SNMP | Simple network management protocol |
| SoDIMM | Small outline dual inline memory module |
| SOHO | Small office/home office |
| SP | Service pack |
| SP1 | Service pack 1 |
| SP2 | Service pack 2 |
| SPDIF | Sony-Philips digital interface format |