Network Fundamentals Glossary

This glossary defines the core terms used throughout the Network Fundamentals section.

The definitions focus on practical understanding within a home network environment.

IP (Internet Protocol)

A network-layer protocol responsible for logical addressing and packet routing. It determines where data should be delivered.

IPv4 (Internet Protocol version 4)

The most widely used IP addressing format (for example: 192.168.1.25).

DHCP (Dynamic Host Configuration Protocol)

A protocol that automatically assigns network configuration parameters to a device:

• IP address
• Subnet mask
• Default gateway
• DNS server

DNS (Domain Name System)

A system that translates domain names (example.com) into IP addresses.

TCP (Transmission Control Protocol)

A connection-oriented transport protocol that:

• establishes a session
• confirms packet delivery (ACK)
• retransmits lost segments
• ensures ordered transmission

Used where reliability is required.

UDP (User Datagram Protocol)

A connectionless transport protocol that:

• does not confirm delivery
• does not retransmit lost packets
• minimizes latency

Used where speed is prioritized.

ACK (Acknowledgment)

A confirmation message used in TCP to verify that a packet has been received. If no acknowledgment is received, retransmission occurs.

LAN (Local Area Network)

A local network within a home or office.

WAN (Wide Area Network)

An external network. In a home context, this refers to the Internet connection provided by an ISP.

ISP (Internet Service Provider)

A company that provides Internet connectivity.

MAC Address (Media Access Control Address)

The physical hardware address assigned to a network interface.

Gateway

A device that enables communication between different networks. In a home network, this role is typically performed by the router.

Default Gateway

The IP address to which traffic is sent when the destination is outside the local subnet.

Router

A device that forwards traffic between networks (LAN ↔ WAN).

Switch

A device that forwards traffic within a local network at the data link layer.

Subnet Mask

Defines the boundaries of a local network segment and determines whether a destination IP belongs to the same subnet.

Packet

The smallest structured unit of data transmitted across a network.

OSI Model (Open Systems Interconnection Model)

A conceptual framework that describes how network communication is structured across multiple layers.