Polarity is a very important concept, especially when it comes to physically building circuits. Whether you’re plugging parts into a breadboard or soldering them to a PCB, it’s critical to be able to identify polarized components and to connect them in the correct direction.
In the realm of electronics, polarity indicates whether a circuit component is symmetric or not. A non-polarized component – a part without polarity – can be connected in any direction and still function the way as you expected. A symmetric component rarely has more than two terminals, and every terminal on the component is equivalent. You can connect a non-polarized component in any direction, and it’ll function just the same.
A polarized component – a part with polarity – can only be connected to a circuit in one direction. A polarized component might have two, twenty, or even two-hundred pins, and each one has a unique function or position. If a polarized component was connected to a circuit incorrectly, at best it won’t work as intended. At worst, an incorrectly connected polarized component will smoke, spark, and be one very dead part.