The Internet of Things is any physical object that connects to the internet and sends or receives data
The Internet of Things — usually shortened to IoT — means devices that are not computers or phones but still connect to the internet and talk to each other or to you. A smart thermostat that learns your temperature preferences and adjusts itself. A refrigerator that tells you when milk is running low. A doorbell camera that sends video to your phone when someone rings it. A fitness tracker that syncs your steps to an app. All of these are IoT devices.
The key difference from older technology is that these devices are networked. They do not just sit in your home doing one job in isolation. They collect data, send it somewhere (usually to a company's servers), receive instructions back, and often talk to other devices. A smart home system might let your thermostat, lights, and door locks all communicate with each other and respond to a single command from your phone.
IoT devices range from obvious ones you buy intentionally to ones embedded in things you already own. Your car may have IoT sensors that report maintenance needs. Your washing machine might send alerts when a cycle is done. Even some light bulbs now have wireless chips built in. The devices themselves are often cheap to manufacture, which is why they are becoming more common — but the real business model is the data they collect and the services built around that data.
Key Takeaways
- IoT devices are physical objects — thermostats, cameras, watches, appliances — that connect to the internet and send data rather than working in isolation.
- Most IoT devices send information to a company's servers, which means the manufacturer collects data about how you use the device and when.
- IoT devices can create security risks if they are not updated regularly, because hackers can use them to enter your home network or steal personal information.
- You control what data an IoT device collects by reading its privacy policy before you buy it and by changing its settings after setup.
How IoT devices collect and use your data
When you set up an IoT device, you usually connect it to your home Wi-Fi and create an account with the manufacturer. From that point on, the device sends information back to the company's servers. A smart speaker records when you use voice commands and what you ask for. A fitness tracker logs your location, heart rate, and sleep patterns. A smart doorbell stores video of everyone who comes to your door. A connected refrigerator may track what food you buy and how often you open the door.
The manufacturer uses this data for several purposes. Some of it improves the device itself — a thermostat learns your habits so it can predict what temperature you want. Some of it trains artificial intelligence systems that the company sells to other businesses. Some of it is sold to advertisers or data brokers, either directly or after being combined with data from other sources. The privacy policy for each device should explain what data is collected, how long it is kept, and who can see it — but these policies are often long and written in legal language that is hard to parse.
You have some control over this. Most IoT devices let you turn off certain features — you can disable the microphone on a smart speaker, turn off location tracking on a fitness watch, or set a camera to record only when you are away. You can also choose not to connect a device to the internet at all, though it will lose its smart features. The trade-off is real: the more data you let the device collect, the more useful it becomes. A thermostat that does not learn your patterns is just a regular thermostat.
Security risks that come with connected devices
Every device that connects to the internet is a potential entry point for hackers. If an IoT device has weak security or is not updated regularly, someone could use it to break into your home network, access your other devices, or steal personal information. This is not theoretical — security researchers regularly find vulnerabilities in smart home devices, and hackers have used compromised IoT devices to launch attacks on other targets.
The risk is higher with cheaper devices, because manufacturers often cut corners on security to keep costs down. A $20 smart plug may have a default password that is the same on every unit, or it may never receive security updates. A $200 device from an established company is more likely to be patched regularly, but it is not may provide. Many people buy an IoT device, set it up, and never update its firmware — the software that runs on the device itself — even though updates often fix security holes.
You reduce this risk by choosing devices from manufacturers with a track record of updates, changing any default passwords when ready, keeping your home Wi-Fi password strong, and checking for firmware updates every few months. Some devices let you update automatically; others require you to do it manually through an app. If a manufacturer stops supporting a device with updates, the security risk grows over time, and you should consider replacing it.
The difference between IoT and smart home devices
IoT is the broad category — any connected device. Smart home devices are a subset of IoT that are specifically designed for homes. A smart thermostat is both IoT and smart home. A connected industrial sensor in a factory is IoT but not smart home. A fitness tracker is IoT but not smart home. The terms are often used interchangeably in marketing, but IoT is the wider umbrella.
Smart home devices are marketed as convenience — you can control your lights from your phone, your door unlocks automatically when you arrive, your heating adjusts without you thinking about it. The real appeal to manufacturers is that smart home devices sit in your private space and collect intimate data about your daily life. They know when you wake up, when you leave, when you are home, what temperature you prefer, what you watch, and who visits. This data is valuable to advertisers and to companies building profiles of consumer behavior.
What information IoT devices typically collect
The data varies by device type, but common categories include location, timing, usage patterns, and personal preferences. A smart speaker knows what time you ask it questions and what you ask about. A connected car knows where you drive, how fast you go, and how often you brake. A smart TV knows what you watch and for how long. A connected scale knows your weight and body composition. A smart doorbell knows who visits and when. A fitness tracker knows your heart rate, sleep quality, and exercise habits.
Some of this data is obvious — you expect a fitness tracker to measure your steps. Some is less obvious — you might not realize that a smart TV is also tracking what you watch, or that a connected appliance is recording how often you use it. The privacy policy should spell this out, but you have to read it. Many people do not, which is why data collection often comes as a surprise later.
The data is usually stored on the manufacturer's servers, not on the device itself. This means the company retains it even after you stop using the device. Some companies keep data indefinitely; others delete it after a set period. Some let you request deletion; others do not. If you are concerned about what data is being collected, read the privacy policy before you buy, and check the settings after setup to see what you can disable.
How to decide if an IoT device is worth the privacy trade-off
Every IoT device involves a trade-off: you get convenience and features in exchange for data collection and some security risk. Whether that trade-off makes sense depends on your own comfort level and the specific device. A smart thermostat that learns your temperature preferences and saves you money on heating bills might be worth sharing your heating habits with the manufacturer. A smart speaker that records everything you say might not be, depending on what you value.
Before you buy, ask yourself: What data will this device collect? Who will have access to it? What could go wrong if that data is breached or misused? What happens if the manufacturer stops supporting the device with updates? Can I disable the features I am uncomfortable with and still use the device? Is the convenience worth the risk?
You can also reduce risk by compartmentalizing. Use an IoT device on a separate network from your computer and phone if your router supports it. Buy from manufacturers with a reputation for security and updates. Avoid connecting devices you do not actually need — a smart plug for a lamp is lower risk than a smart speaker with a microphone. And remember that you can always choose not to connect something to the internet. A regular thermostat, a regular doorbell, and a regular scale all work fine without sending data anywhere.
Frequently Asked Questions
Do I need to worry about hackers using my smart home devices to get into my network?
It is possible but not inevitable. The risk is real — security researchers have demonstrated ways to compromise smart home devices — but it requires the device to have a specific vulnerability and the hacker to target you specifically. The more realistic risk is that a compromised device slows down your network or is used to attack other targets. You reduce the risk by using strong Wi-Fi passwords, updating device firmware regularly, and choosing devices from manufacturers that support updates.
Can I use an IoT device without connecting it to the internet?
Some devices can work locally — a smart light bulb can be controlled by a local hub without sending data to the cloud. Most cannot. A smart thermostat needs internet to send you alerts or let you control it remotely. A fitness tracker needs internet to sync data to an app. If a device requires internet to function, you cannot use it without accepting that data will be sent to the manufacturer's servers.
What should I do if a manufacturer stops updating a device I own?
The device becomes a growing security risk over time as new vulnerabilities are discovered and not patched. If you rely on it, consider replacing it with a newer model from a manufacturer with a better track record of updates. If you keep using it, isolate it on your network if possible and monitor for signs of compromise — unusual network activity, unexpected behavior, or alerts from your router.
How do I know what data my IoT device is collecting?
Read the privacy policy before you buy, and check the device settings after setup. Most manufacturers have a privacy page on their website that explains what data is collected, how long it is kept, and who can access it. Many devices also have settings that let you disable specific features — microphones, location tracking, or cloud storage. If the privacy policy is unclear or the manufacturer will not explain what data is collected, that is a sign to buy from a different company.
Is it safe to use IoT devices in a rental apartment?
Yes, as long as you own the devices and can remove them when you move. Rented smart home systems that are built into the apartment are different — you do not control the security or the data collection. If your landlord has installed a smart lock or camera, ask them about the privacy policy and who has access to the data. You can also add your own devices (a smart plug, a portable camera) that you control and take with you.