| A | B |
|---|
| Layer 1 | Physical |
| Layer 2 | Data Link |
| Layer 3 | Network |
| Layer 4 | Transport |
| Layer 5 | Session |
| Layer 6 | Presentation |
| Layer 7 | Application |
| OSI | Open Systems Interconnect |
| Application Layer | All computer communications start here |
| Presentation Layer | Manages security issues (encryption) |
| Session Layer | Establishes dialog control between two computers |
| Transport Layer | Handles error recognition and recovery |
| Network Layer | Translates logical addresses into physical addresses |
| Data Link Layer | Responsible for transferring frames from one computer to another, without errors |
| Physical layer | wires, cables and fiber optics |
