Networks are classified based on three key factors: their geographic scope (how much physical area they cover), their scale (number of devices and users), and their purpose (what specific problem they solve). Understanding these distinctions is foundational for the CCNA exam and for designing networks in the real world.
Network Scale (smallest to largest)
------------------------------------
PAN LAN CAN MAN WAN
(desk) (building) (campus) (city) (country/world)
|<-1m->|<----100m-->|<---1km-->|<--50km-->|<-unlimited->|
Special Purpose:
SAN = Storage Area Network (data center)
VPN = Virtual Private Network (logical overlay)
IoT = Internet of Things (sensor/device mesh)
A LAN connects devices within a single building, floor, or small campus. It is the most common network type and forms the foundation of every enterprise, school, and home network.
Attribute
Details
Geographic scope
Single room, floor, building, or small campus (up to ~1 km)
Speed
100 Mbps to 10+ Gbps (Fast Ethernet, Gigabit, 10GbE)
Ownership
Owned and managed by a single organisation
Technologies
Ethernet (IEEE 802.3) for wired; Wi-Fi (IEEE 802.11) for wireless
Cost
Low — uses inexpensive switches and cabling
Typical topology
Star (central switch)
Real-world examples: An office network connecting PCs, printers, and servers. A school computer lab. A home network connecting laptops, phones, and a smart TV via Wi-Fi.
2. Wide Area Network (WAN)
A WAN connects multiple LANs across large geographic distances — cities, countries, or continents — using third-party carrier infrastructure such as leased lines, MPLS, or the public Internet.
Attribute
Details
Geographic scope
Cities, countries, or continents — theoretically unlimited
Speed
Lower than LAN — typically 1 Mbps to 10 Gbps depending on link type
Ownership
Infrastructure provided by ISPs or telcos; leased by the organisation
Technologies
MPLS, SD-WAN, leased lines, Metro Ethernet, 4G/5G, satellite
Cost
High — paying for long-distance carrier infrastructure
Latency
Higher than LAN — especially for intercontinental links
Real-world example: A multinational company connecting its London, New York, and Singapore offices over MPLS. The Internet itself is the world's largest WAN.
3. Metropolitan Area Network (MAN)
A MAN spans a city or large campus — bigger than a LAN but smaller than a WAN. It is typically owned by a city, government, or large enterprise and connects multiple buildings across a metropolitan area.
Attribute
Details
Geographic scope
5–50 km — city or large campus
Speed
Medium to high — often uses fibre optic backbone
Technologies
Metro Ethernet, fibre ring (SONET/SDH), WiMAX
Ownership
City government, university system, or large enterprise
Real-world example: A city-wide fibre network connecting all public schools and libraries. A university system connecting multiple campuses across a city.
4. Personal Area Network (PAN)
A PAN is a very short-range network centred around a single person and their personal devices — typically spanning a desk or a few metres at most.
Attribute
Details
Geographic scope
Up to ~10 metres around one person
Technologies
Bluetooth (most common), NFC, infrared, USB tethering
Very low — uses built-in radios on consumer devices
Real-world example: A smartphone connected via Bluetooth to wireless earbuds and a smartwatch simultaneously. A laptop tethered to a mobile phone for internet access.
5. Campus Area Network (CAN)
A CAN connects multiple buildings and LANs within a defined, limited geographic area such as a university campus, business park, hospital complex, or military base — owned entirely by a single organisation.
Attribute
Details
Geographic scope
Multiple buildings within ~1–5 km
Speed
High — typically Gigabit or 10 Gigabit fibre backbones
Ownership
Single organisation (university, hospital, corporation)
Topology
Hierarchical star — core/distribution/access layers
Real-world example: A university connecting all departments, libraries, dormitories, and research centres on campus with a centralised core switch infrastructure.
6. Storage Area Network (SAN)
A SAN is a specialised, high-speed network dedicated exclusively to connecting servers to shared storage systems. SANs are isolated from the general LAN to ensure storage traffic does not compete with user traffic.
Attribute
Details
Purpose
Provide fast, dedicated access to shared storage (disk arrays, tape libraries)
Scope
Data centre — typically within a single building or campus
Speed
Very high — 16/32 Gbps Fibre Channel; 10/25/100 Gbps iSCSI
Technologies
Fibre Channel (FC), iSCSI, FCoE (Fibre Channel over Ethernet)
Key benefit
Multiple servers share one storage pool; storage appears as local disk
Real-world example: A data centre using a Fibre Channel SAN so 50 servers can all access a centralised storage array for databases and virtual machine disk images.
7. Virtual Private Network (VPN)
A VPN is not a physical network type but a logical overlay — a secure, encrypted tunnel built on top of an existing network (usually the public Internet) that makes remote users and sites appear to be directly connected to a private network.
Attribute
Details
Type
Logical overlay — not a separate physical infrastructure
Security
Encrypts all traffic — protects data over untrusted public networks
Low to medium — uses existing internet infrastructure
Real-world example: A remote employee uses a VPN client to create an encrypted tunnel to HQ — their laptop appears to be inside the office network, accessing internal file servers and applications securely.