What is a software driver?

The term "Software driver" (or "pilote logiciel" in French) refers to a software solution designed to create a communication interface between the operating system and an external digital device.

Let's take a mouse for example. Before being a computer peripheral, it is first and foremost an electronic circuit.

It's because it's equipped with a connector compatible with a computer, and because there is a driver to convert its digital signals into data understandable by the operating system, that it becomes a usable external device.

To simplify things, here is a diagram of the data transmission to understand where the driver fits in:

The connector (USB for example) is just a connection point, it may eventually standardize a few values (the supply voltage for example), but once plugged in, it's the device's electronic circuit that will decide the format of the data, its content, the refresh rate, and many other things.

The operating system, for its part, won't be able to guess this information in advance, and that's where the software driver comes into play.

Once installed, the driver will activate for the device in question and will know how to decode the information sent by the device, because it will have been developed specifically for it.

Once the data has been retrieved, it can normalize it and send it to the operating system.

Do you need to install a driver for every device?

No, not necessarily.

First, there are analog devices (usually audio), which will send a frequency-based signal that will be digitized (or not) directly by the system.

And for standard digital devices (keyboard, mouse, webcam, etc.), most operating systems come packaged with generic software drivers, which allows you to start using the device right out of the box.

This is sometimes called "Plug and Play."

But of course, it's up to the hardware manufacturer to ensure that their device is compatible with the generic drivers, and this can limit your hardware to its basic features, leaving inactive any additional features not supported by the generic driver.

The media keys on certain keyboards, for example.

That's why it's always recommended to install manufacturer drivers and keep them updated, to avoid any degradation of features as well as any potential security vulnerabilities!