What is Networking? A Complete Guide for Tech Enthusiasts and Professionals

Computer networking is the hidden force behind everything from websites and apps to cloud computing and online games. No matter whether you are a developer, IT professional, or just a curious student, knowing the basics of networking is indispensable for doing work with today's technologies.

This blog takes you through all the basics you'll need to learn about networking in order to get going — IP addresses, protocols, DNS, ports, routing, networking layers, firewalls, and more — described succinctly, clearly, and sensibly.

What Is Computer Networking?

Computer networking is the process of linking computing devices (e.g., smartphones, computers, servers, routers) to exchange data and resources. The devices communicate using standardized protocols to exchange data over physical or wireless media.

The best-known network is the internet, a vast global network of linked computers and servers.

The Building Blocks of Networking

1. IP Addresses

An IP address (Internet Protocol address) identifies a device on a network uniquely, similar to a phone number or home address.

There are two versions:

IPv4: 32-bit address (e.g., 192.168.0.1)
IPv6: 128-bit address (e.g., 2001:db8::1), created in response to IPv4 exhaustion

2. MAC Addresses

The MAC (Media Access Control) address is an exclusive hardware identifier given to a network interface card (NIC). It is at the data link layer, and is utilized for communication within the local network (LAN).

Types of Networks

Type	Description
LAN (Local Area Network)	Covers small areas such as homes or offices
WAN (Wide Area Network)	Spreads large areas, interconnects several LANs
PAN (Personal Area Network)	Small network surrounding an individual (e.g. Bluetooth devices)
MAN (Metropolitan Area Network)	Span across a city or campus
Internet	A worldwide collection of interconnected WANs

Protocols and the OSI Model

Network communication follows a series of rules known as protocols, and many are layered according to the OSI Model (Open Systems Interconnection) — a theoretical model with 7 layers:

Physical Layer – Hardware: cables, switches, voltages
Data Link Layer – MAC addresses, switches
Network Layer – IP addresses, routing
Transport Layer – TCP/UDP, ports
Session Layer – Connection management
Presentation Layer – Data format (encryption, compression)
Application Layer – User-facing protocols (HTTP, FTP, DNS)

In actual networking, we usually talk about the TCP/IP model, which breaks up the above into 4 layers.

Common Protocols You Should Know

Protocol	Purpose
IP (Internet Protocol)	Addressing and routing data packets
TCP (Transmission Control Protocol)	Reliable, connection-oriented data transfer
UDP (User Datagram Protocol)	Faster, connectionless transfer (used for games, video calls)
HTTP/HTTPS	Web communication (HTTPS is secured through SSL/TLS)
FTP/SFTP	Transferring files
SSH	Secure remote access to servers
DNS	Translates domain names (e.g. google.com) into IP addresses
DHCP	Provides dynamic IP addresses to devices on a network
ICMP	Used for diagnostics (e.g., ping, traceroute)

Ports and Services

Ports enable multiple services to be run on a single IP address by assigning a number to each process.

Port 80 – HTTP
Port 443 – HTTPS
Port 22 – SSH
Port 53 – DNS
Port 25/587 – SMTP (email sending)

Ports range from 0 to 65535. Ports 0–1023 are "well-known ports."

Domain Name System (DNS)

DNS is the internet phonebook.

When you enter www.example.com:

Your computer asks a DNS resolver.
It determines the IP address of that domain.
Your device establishes a connection using TCP/IP to that IP.

Without DNS, you'd need to remember IPs instead of domain names.

Routing and Switching

Switches function on the data link layer. They link devices in a LAN and forward based on MAC addresses.
Routers function at the network layer. They link various networks (such as your home network to the internet) and forward based on IP addresses.

The default gateway will generally be your router — it sends traffic from your device out to the internet.

Firewalls, NAT, and Security

Firewalls

A firewall is an access control system that inspects and controls incoming and going traffic according to defined rules. It prevents unwanted access.

NAT (Network Address Translation)

NAT enables numerous devices on a private network (e.g., 192.168.x.x) to use one public IP address. It's the way in which your home router links numerous devices to the internet.

VPNs

A VPN (Virtual Private Network) encrypts your traffic and routes it through a secure server, often used for privacy and secure remote access.

Tools for Troubleshooting

Tool	Function
`ping`	Tests reachability of a host
`traceroute` / `tracert`	Shows path packets take to reach a host
`ipconfig` / `ifconfig`	Displays IP configuration
`netstat`	Shows active connections and listening ports
`nslookup`	DNS query tool
`nmap`	Scans network for open ports and devices

Real-World Applications

Web Hosting: Understanding how web servers use TCP/IP and HTTP/S
Game Development: Utilizing UDP for low-latency real-time updates
Cybersecurity: Firewalls, traffic analysis, intrusion prevention
Cloud Computing: Networking is integral to deploying scalable apps and APIs

Summary

Concept	Key Point
IP Address	Identifies a device on a network
Protocol	Rules for data communication
Port	Identifies a particular service on a device
DNS	Resolves domain names to IPs
Router/Switch	Routes data between networks / within a LAN
Firewall/NAT	Manages traffic and allows multiple devices over one IP

Conclusion

Computer networking is vast and fundamental — the foundation of all we do on the internet. Knowing the basics — from IPs and protocols to routing and DNS — gives you what it takes to craft, diagnose, and protect systems dependent on the internet.

No matter your aim to go deep into backend development, cybersecurity, DevOps, or system administration, networking is a fundamental skill that is well worth learning.