Many makers start in electronics by using pre-built modules: typically a module with a microcontroller (e.g., Arduino, Raspberry Pi, ESP32, or STM32 variant) and another board with some type of I/O (e.g., an accelerometer, camera, temperature sensor, or relay). They join these boards together with wire links, often without the need for soldering, to make a functional prototype. So far so good. The advantages of this approach are flexibility, speed, and low cost: They can keep making changes until they have the required functionality.

However, projects like this can be difficult to package in a compact manner and inevitably contain unneeded circuitry, and the wire links might not be durable over time. It can also be an expensive solution if more than one prototype is required. If you want your project to use a component not available on a module, run from batteries, have custom displays, or any variety of requirements, the need for a more flexible solution becomes yet more apparent.

You might move on to other prototyping systems, like soldering components onto a stripboard and wiring them up with soldered wire links. This approach worked well when I started out in the business 40 years ago, but today, many interesting components are just not available in through-hole form on the 2.5mm/0.1-inch pitch that was the standard back then.

[...]