What is the Internet of Things (IoT)?
In short: The Internet of Things (IoT) is the network of physical objects that sense or change the world and exchange data over a network. It grew from machine-to-machine (M2M) systems and cheap embedded chips. The huge number and variety of devices is what makes IoT both useful and hard to secure.
A working definition
The Internet of Things (IoT) describes physical objects that contain electronics, software and a network connection so they can sense something, act on something, or both, and share data with other systems. A smart thermostat measures room temperature and switches the heating. A parcel tracker reports its location. A soil probe tells a farmer when a field is dry.
What makes these devices "IoT" rather than ordinary computers is their purpose. They are usually built to do one job, run on limited hardware, often have no screen or keyboard, and are expected to work unattended for years.
How the idea grew
Connected machines are not new. Factories and utilities used supervisory control and data acquisition (SCADA) systems and machine-to-machine (M2M) links over phone lines and early mobile networks for decades. Three changes turned this into IoT as we know it:
- Cheap chips. Microcontrollers with built-in Wi-Fi or Bluetooth now cost very little, so almost any product can be connected.
- Ubiquitous networks. Home broadband, mobile data and new low-power radios mean a device can reach the internet almost anywhere.
- Cloud platforms. Storing and analysing data from millions of devices no longer needs your own data centre.
The term "Internet of Things" is usually credited to the late 1990s, in the context of tagging goods with radio-frequency identification (RFID). Since then it has broadened to cover any connected sensor or actuator.
Why scale changes everything
Industry analysts count connected IoT devices in the billions, and the number keeps rising. You do not need an exact figure to see the consequence: when one design flaw is copied into a million identical cameras, it becomes a million vulnerable cameras. Scale also means huge volumes of data, many owners who never update firmware, and devices that stay in service long after the maker stops supporting them.
| Ordinary IT | Typical IoT device |
|---|---|
| General-purpose laptop or server | Single-purpose device |
| Plenty of CPU, memory and power | Small processor, little memory, often battery powered |
| Managed by IT staff, patched monthly | Often unmanaged, updates rare or manual |
| Replaced every few years | May run for ten years or more |
Examples you already use
At home you may have a video doorbell, smart plugs or a voice assistant. At work there may be IP cameras, badge readers, smart TVs in meeting rooms and building management sensors. Each of these is a small computer on your network, and each needs the same care as a laptop: a known owner, a strong unique password, updates and a sensible place on the network.
Tip: a quick exercise is to list every connected device in your home or office. Most people find two or three times more than they expected, which is the first lesson of IoT security: you cannot protect what you have not counted.
Practice
Is a laptop an IoT device?
Name two developments that turned M2M into modern IoT.
Why does the scale of IoT matter for security?
Key takeaways
- IoT devices sense or act on the physical world and share data over a network.
- They are usually single-purpose, constrained, unattended and long-lived.
- IoT grew from M2M and SCADA, helped by cheap chips, networks and cloud.
- Scale turns one design flaw into millions of vulnerable devices.
- Start any IoT security work by counting the devices you actually have.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.