| 略語 | フルスペル |
|---|---|
| O2O | Online to Offline |
| OASIS | Organization for Advancement of Structured Information Standards |
| OCR | Optical Character Reader |
| OCSP | Online Certificate Status Protocol |
| ODBC | Open DataBase Connectivity |
| OLAP | OnLine Analytical Processing |
| OLE | Object Linking and Embedding |
| OP25B | Outbound Port 25 Blocking |
| OS | Operating System |
| OSI基本参照モデル | Open Systems Interconnection |
| OSS | Open Souece Software |
| OTP | One Time Password |