The concept is the Internet of Things, commonly called IoT. It refers to a network of physical devices embedded with sensors, software, and network connectivity that allow them to collect and share data. A smart refrigerator is one of the most recognizable examples: it connects to your home Wi-Fi, tracks what’s inside, and communicates with your phone or other devices. As of 2025, an estimated 21.1 billion IoT devices are connected worldwide, a number projected to reach 39 billion by 2030.
What the Internet of Things Actually Means
IoT isn’t a single technology. It’s the idea that everyday physical objects can be equipped with small computers, sensors, and internet connections so they “talk” to each other and to you. Your fitness tracker sending step counts to your phone, a thermostat adjusting temperature based on weather forecasts, a doorbell streaming video to your tablet: all of these are IoT in action. The common thread is that a previously “dumb” object gains the ability to sense its environment, process information, and share it over a network.
IoT devices range from simple consumer gadgets like smart light bulbs to complex systems used in factories, hospitals, and city infrastructure. The consumer side, often called the “smart home,” is where devices like smart refrigerators, connected ovens, robotic vacuums, and voice assistants live. The industrial side covers things like sensors on oil pipelines, GPS trackers on shipping containers, and automated farming equipment. The underlying concept is the same regardless of scale.
How a Smart Refrigerator Uses IoT
A smart refrigerator illustrates how IoT works in a practical, everyday way. Door sensors scan items as they enter and exit, recording the type, quantity, and expiry date of each product. When something is about to expire, the fridge sends a notification to your phone or plays an audio alert. It maintains a running inventory of what you have, which means it can generate a weekly shopping list based on items that are running low.
More advanced models go further. They store nutritional data for common foods and can suggest recipes based on what’s currently inside. If a user enters personal details like weight, height, age, or existing health conditions such as diabetes or high blood pressure, the refrigerator can flag foods that aren’t appropriate and recommend alternatives. Some systems track calorie intake over time and help with meal planning by calculating nutrients from previous meals and designing balanced options for the week ahead.
This is only possible because the refrigerator is connected. It pulls recipe databases from the cloud, syncs your shopping list with a grocery app, and receives software updates that improve its features over time. Without an internet connection, it’s just a cold box.
Energy Savings Through Connected Appliances
One of the more tangible benefits of IoT appliances is energy management. Smart refrigerators, dishwashers, washers, and dryers can participate in what’s called demand response, where they automatically adjust their behavior during peak energy hours when electricity costs the most. A smart refrigerator, for example, can delay its defrost cycle, reduce compressor run time, or shift to an energy-saver temperature mode during peak periods.
A connected dishwasher might delay its wash cycle until off-peak hours. A smart washer can switch to cold water and shorter cycles. A hybrid water heater in one pilot program dropped from 4,500 watts in standard mode to just 800 watts during peak demand. Across a home, these small adjustments add up. In trials, households with demand-response appliances saw a 27% reduction in energy use during peak hours and a 6% drop in daily energy costs. A home energy manager can coordinate all of these devices, scheduling them around electricity rates, weather forecasts, and even solar panel output.
How Different Brands Work Together
A longstanding frustration with smart home devices has been compatibility. A smart plug from one brand might not work with a voice assistant from another, forcing you to pick an ecosystem and stick with it. A protocol called Matter, developed by a coalition of major tech companies, directly addresses this problem.
Matter is a universal connectivity standard that lets devices from different manufacturers communicate natively with each other. It’s supported by Amazon Alexa, Apple Siri, Google Assistant, and many other platforms. The practical result is that you can buy a smart refrigerator from one company, a thermostat from another, and a voice assistant from a third, and they all work together without workarounds. For consumers, it removes the guesswork from purchasing decisions. For manufacturers, it simplifies development because they build to one standard instead of many.
Supporting Independent Living for Older Adults
IoT devices have a particularly meaningful role for older adults living independently. Smart home sensors can detect inactivity, falls, or unusual patterns and alert caregivers automatically. Health monitoring devices track vital signs and medication schedules. Voice assistants let someone call for help, set reminders, or control appliances without needing to reach a switch or navigate a phone screen.
In this context, a smart refrigerator that tracks food expiry and suggests balanced meals isn’t just convenient. For someone managing a chronic condition or experiencing mild cognitive decline, these automated nudges can prevent spoiled food from being consumed and support dietary goals set by a healthcare provider. Caregivers often have high expectations for these devices because the stakes are real: a missed medication alert or an undetected fall can have serious consequences.
Security Risks With Connected Devices
Every device connected to your network is a potential entry point for hackers, and IoT devices have a particularly poor track record. Research estimates that, on average, 25 vulnerabilities exist in every IoT device. Common weaknesses include factory-set passwords that users never change, unencrypted data transmission, outdated firmware, and insecure configuration settings. Smart door locks, cameras, and even refrigerators can be exploited if they lack strong authentication or secure communication protocols.
You can reduce risk with a few straightforward steps. Rename your router so it doesn’t include personal information. Use a strong, unique password for your Wi-Fi network. Make sure network traffic is encrypted. Update device firmware whenever updates become available, since these patches often fix known security holes. Some newer routers let you create a separate network for IoT devices, isolating them from your computers and phones so that a compromised smart appliance can’t be used as a gateway to more sensitive data.
Why IoT Keeps Growing
The number of connected IoT devices grew 12% in 2024, reaching 18.5 billion globally. The 14% growth expected in 2025, bringing the total to 21.1 billion, reflects continued adoption across both consumer and industrial sectors. By 2035, the count is projected to exceed 50 billion. Standards like Matter are accelerating adoption by lowering the barrier for both manufacturers and buyers, while falling sensor costs make it cheaper to add connectivity to appliances that previously had none.
For the average household, this means the number of “smart” options on the shelf will keep expanding. Understanding that all of these devices operate on the same foundational concept, the Internet of Things, makes it easier to evaluate what you actually need, how the pieces fit together, and what trade-offs in privacy and security come along with the convenience.