Think of 433MHz as a radio station frequency, but for gadgets instead of radio shows. This frequency is popular for all sorts of home-based wireless projects. From garage door openers to simple remote controls, many devices use this frequency because it's reliable and doesn't cost much.
Imagine you're into DIY projects and you want to turn on your living room lights without getting off the couch, or perhaps you want a simple system that lets you know when the mail arrives. 433MHz modules are perfect for these kinds of tasks. They're super affordable and pretty straightforward to set up, so you don't have to be a tech genius to use them.
The range of these modules can vary. In a clear line of sight, some modules can send signals up to a couple of kilometers. But inside a house, with walls and other objects in the way, it’s usually less—more like tens of meters. Want to extend that range? You can do so by adding a more powerful antenna.
There are mainly two types you'll come across. One is the transmitter, which sends out the signals. The other is the receiver, which picks those signals up. Some modules can do both, sending and receiving signals; these are called transceivers. You can use them in more complex projects where devices need to talk back and forth, like a two-way remote control for a drone.