Firmware: what it is and why you should update your devices

Firmware is software built into a device that controls how it works. On a phone, the whole system is often called firmware; on routers, earbuds, watches and TVs it is the device's internal program.

Firmware is like a music box cylinder

In plain words

A device is like a music box, and the firmware is the spiked cylinder that decides which tune it plays. A new cylinder means a new tune: bugs fixed, new features, better sound. A homemade cylinder (custom firmware) might play something interesting - or break the box.

How it works

Firmware is stored in the device's flash memory.
It starts when the device is switched on and controls the hardware.
The manufacturer releases updates with fixes and features.
Updates arrive "over the air" (OTA) or via an app or computer.
You must not cut the power during an update, or the device may be bricked.

Do not cut the power during an update

Where you'll see it

On phones: Settings - System update. On routers: the web interface or app. On earbuds and watches: the companion apps (Galaxy Wearable, Garmin Connect, Sony Headphones). On TVs: the "Software update" section.

Does it matter when buying

Yes - firmware updates close security holes, especially on routers. I recommend turning on automatic updates wherever you can and updating your router at least every few months. Before updating a phone, make sure it has at least 50% charge and a backup.

Myths

Myth: Updates always make a device worse. Reality: Most of the time they fix bugs and vulnerabilities.
Myth: Custom firmware is safe. Reality: It can void your warranty, weaken security and break banking apps.

FAQ

What is an OTA update?

An "over-the-air" update - delivered over the internet without a cable.

What if an update stalls?

Do not switch the device off; wait, and if it fails, contact a service centre.

How do I update my router's firmware?

In its web interface or app, under "Update" or "Firmware".