What Is the Internet of Things? Everyday Connected Devices

The Internet of Things, usually shortened to IoT, describes everyday objects that are connected to the internet so they can collect and share data. A smart thermostat, a fitness tracker and a connected doorbell are all examples.

Key takeaways

• IoT devices combine sensors, a small computer and a network connection.
• They send data to apps or cloud services and can sometimes be controlled remotely.
• Uses range from smart homes to farming, factories and health monitoring.
• Weak security on cheap devices is a common risk.
• A few simple habits make a connected home safer.

What makes a device part of the IoT

Three ingredients are typical. Sensors measure something, such as temperature, motion, light or location. A small processor handles basic logic. A communication link, such as Wi-Fi, Bluetooth, Zigbee or a mobile network, connects the device to an app or online service. Some devices also have actuators that do something in the real world, like switching a light or locking a door.

Everyday examples

In the home, smart thermostats learn when you are in and adjust heating, smart speakers respond to voice commands and connected cameras and locks add convenience. Wearable devices track steps and heart rate. In cars, sensors report maintenance needs. Cities use connected sensors to monitor traffic and air quality, farms use soil sensors to guide watering, and factories track equipment health to schedule repairs before breakdowns.

How data flows

A typical device collects readings and sends them over the network to a cloud service, where software stores and analyses them. Your phone app then displays results or sends commands back. Some systems process data locally on the device or a nearby hub, which can reduce delay and limit how much information leaves the home, an approach known as edge computing.

Benefits

Connected devices can save energy, improve safety, give useful information about health or equipment and automate boring tasks. For people with limited mobility, voice control or remote operation can be especially helpful.

Risks to consider

IoT devices are often small and cheap, and some are sold with weak security, default passwords or no regular updates. A compromised camera or router can expose private information or be used in attacks on other systems. Devices also collect personal data, so it is worth understanding what is stored and who can see it.

Sensible habits

• Change default passwords and use unique ones.
• Install updates and replace devices that no longer receive them.
• Put smart devices on a separate guest or IoT network if your router supports it.
• Turn off features and permissions you do not use.
• Buy from manufacturers that publish security support policies.

Communication standards

Connected devices talk in different ways. Wi-Fi carries a lot of data but uses more power, so it suits cameras and smart speakers. Bluetooth Low Energy is designed for small bursts of data from wearables and sensors. Zigbee, Z-Wave and Thread are low-power mesh networks in which devices relay messages for each other, which is common in smart-home lighting and sensors. For long-range, low-power uses such as agricultural sensors, technologies such as LoRaWAN and narrowband cellular IoT can reach many kilometres. In 2022, the industry launched Matter, a standard intended to let devices from different brands work together across ecosystems.

Health and agriculture

In healthcare, wearables track heart rate, activity and sleep, and some medical devices send readings, such as blood glucose or blood pressure, to clinicians for remote monitoring. These can help people manage long-term conditions at home, but accuracy and privacy need care. In farming, soil moisture sensors, weather stations and drones help growers use water, fertiliser and pesticides more precisely, saving costs and reducing environmental harm. Livestock can be monitored with collars or ear tags that track movement and health.

Industrial uses

Factories and utilities were early adopters. Sensors on motors, pumps and turbines measure vibration, temperature and pressure so that maintenance can be done when needed, called predictive maintenance, instead of on a fixed schedule or after a breakdown. Digital twins, virtual models fed by sensor data, let engineers test changes before applying them. In cities, connected streetlights, parking sensors and waste bins aim to reduce energy use and congestion, although such systems raise questions about surveillance.

Privacy and regulation

Connected devices collect data about homes and habits, so privacy matters. Governments are starting to set minimum security rules. In the United Kingdom, a law that came into force in 2024 bans default passwords on consumer smart devices and requires manufacturers to publish how long they will provide security updates. The European Union has adopted similar requirements through new cybersecurity legislation, and other countries are creating labels to show that a product meets security standards. These rules are still developing.

Choosing devices wisely

Before buying a smart device, check how long the manufacturer promises updates, whether it works locally without a cloud account, what data it collects and whether it uses open standards that let you switch brands. Avoid devices with no way to change the default password. Read privacy settings and turn off features you do not need. A smaller number of well-supported devices is usually better than a house full of cheap, unsupported ones.

Frequently asked questions

Do IoT devices always need the internet?

Some work locally, but many need a connection for remote control, updates or cloud features.

Is a smart speaker always listening?

It listens for a wake word. Manufacturers describe different privacy controls, and settings let you review or delete recordings in many cases.

What is a smart home hub?

It is a device that connects several smart products and lets them work together, sometimes processing commands locally.

What is Matter?

Matter is an industry standard for smart-home devices, backed by many large technology companies. It aims to make products from different manufacturers work together and be controlled by different apps, with better local control and security.

What happens if the company stops supporting my device?

The device may stop receiving security updates and, if it depends on a cloud service, could stop working altogether. Choosing products with published support periods and local control options reduces this risk.

Can IoT devices be hacked?

Yes, especially those with weak or default passwords and no updates. Attackers have used large numbers of poorly secured devices in attacks. Keeping firmware updated, changing passwords and using a separate network for smart devices lower the risk.

Sources and further reading

• Internet of things (Wikipedia)
• CISA: Securing the Internet of Things