## glossary
What is IoT?
IoT (Internet of Things) is the network of physical objects equipped with sensors, software and connectivity, capable of collecting data from the environment and exchanging it with other systems over the internet. The idea is to extend connectivity beyond computers and phones.
In practice, that spans everything from an app-controlled light bulb to sensors that monitor vibration in industrial turbines and anticipate failures before they happen.
The layered architecture
- Devices — sensors that measure (temperature, humidity, motion, consumption) and actuators that act (switch on, open, adjust).
- Connectivity — how the data travels: Wi-Fi, Bluetooth, LoRaWAN, Zigbee, NB-IoT cellular networks.
- Gateway — aggregates local devices, does pre-processing and translates protocols.
- Platform — ingests, stores and processes the data at scale in the cloud.
- Application — dashboards, alerts and automations that turn data into decisions.
Protocols, and why not HTTP
IoT devices tend to have little memory, limited processing power and run on batteries — sometimes for years. HTTP is far too verbose for that context. The dominant standard is MQTT, a lightweight publish-subscribe protocol with minimal per-message overhead.
import mqtt from 'mqtt';
const cliente = mqtt.connect('mqtts://broker.exemplo.com:8883', {
username: process.env.MQTT_USER,
password: process.env.MQTT_PASS,
});
// the sensor publishes to a hierarchical topic
cliente.publish(
'fabrica/linha-2/prensa-07/temperatura',
JSON.stringify({ valor: 78.4, unidade: 'C', ts: Date.now() }),
{ qos: 1 }
);
// anyone interested subscribes to whatever pattern they want
cliente.subscribe('fabrica/+/+/temperatura');The hierarchical topic structure and the subscription model let new consumers join without the device ever knowing they exist — a decoupling that becomes essential when there are thousands of sensors.
Security: the weakest point
IoT has a poor security track record, and the reasons are structural. Many devices leave the factory with a default password nobody changes. Manufacturers abandon support and stop shipping updates. Limited processing power makes robust encryption harder. And the device is usually physically accessible to anyone willing to open it.
The practical result has been botnets made up of hundreds of thousands of compromised cameras and routers. The essential mitigations are unique credentials per device, signed remote updates, always-encrypted communication and network segmentation that isolates the devices from the rest of the infrastructure.
Edge computing and the volume of data
Sending everything to the cloud is expensive in bandwidth and adds latency that is unacceptable in control applications. Hence the growth of processing at the edge: the gateway filters, aggregates and decides locally, sending the cloud only what is relevant. A sensor that measures every second can transmit just the per-minute average and the out-of-pattern events. The full picture is in internet of things and, on the hardware side, in embedded systems.
## faq
Frequently asked questions
What is the difference between IoT and embedded systems?
An embedded system is a dedicated computer inside a piece of equipment, connected or not. IoT is the subset of those systems that connects to a network to exchange data. Every IoT device is embedded; not every embedded system is IoT.
Which protocol should an IoT project use?
MQTT is the default choice for telemetry, being lightweight and decoupled. CoAP serves even more constrained devices. For physical connectivity, LoRaWAN covers long distances with low power consumption, while Wi-Fi delivers more bandwidth at the cost of battery.
Is industrial IoT different from home IoT?
Yes, considerably. IIoT demands far greater reliability, tolerance of harsh environments, deterministic latency in control applications and life cycles of ten years or more. Home devices prioritize cost and ease of installation.
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