Stage 2: AC vs DC

Every electrical system you encounter uses either alternating current (AC) or direct current (DC) — and often both. In this stage you will learn what makes each type unique, why the power grid settled on AC, and how everyday devices convert between the two.

We start with the basics: what DC is and where you find it (batteries, solar panels, electronics), then move to AC and the sine wave that defines it. You will compare the two side by side, discover why frequency and hertz matter, and finish by spotting AC and DC sources all around your home.

By the end of this stage you will confidently know which type of current powers any device you pick up — and understand the role of power supplies, inverters, and transformers that bridge the AC and DC worlds.