Network
- Router
- 
Outside world <→ Router <→ Inside world 
- VLAN
- 
Level 2 segmentation of a network In a more general sense, VLAN provides logical segmentations of networks. 
- Subnet
- 
Level 3 segmentation of a network 
- CIDR
| 32 | 1 | 
| 31 | 2 | 
| 30 | 4 | 
| 29 | 8 | 
| 28 | 16 | 
| 27 | 32 | 
| 26 | 64 | 
| 25 | 128 | 
| 24 | 256 | 
| 16 | 65536 | 
| 14 | 262142 | 
ACI
ACI stands for Application Centric Interface, a network microsegmentation system by Cisco.
Tenant
A configuration space with some access defined. Can be related to VDCs (Virtual Device Context)