Electricity, in plain terms.

Everything else builds on these ideas. Get comfortable with voltage, current, and resistance and the rest of electronics gets much easier.

1. 1Voltage, current & resistanceVoltage is a difference in potential, current is the flow of charge, resistance opposes it. What each one means and how to measure them on a real board.1 min read·3 questions
2. 2Ohm’s law & powerInteractiveV = I × R and P = V × I, and how to use them to size a resistor, pick an LED series resistor, and catch parts that will run hot before you build.1 min read·4 questions
3. 3Ground & referencesGround is the reference every other voltage is measured against, not a magic sink. Signal, chassis, and earth ground, and why they are not interchangeable.1 min read·2 questions
4. 4AC vs DCDirect current flows one way, alternating current reverses periodically. Frequency, RMS, and where each shows up on a board and in the wall socket.1 min read·2 questions
5. 5Shorts, opens, conductors & insulatorsA short is an unintended low-resistance path, an open is a broken one. How to recognise both, and why conductors and insulators sit on a spectrum.1 min read·2 questions