Theory of Electronics The following sections cover the basic principles, ideas, concepts, laws, and formulas behind electronics. Don’t be tempted to construct an electronics-based career or hobby on a weak foundation. Fully understanding these basic theories will allow you to build that skyscraper upon a firm foundation of concrete knowledge.     CIRCUITS EXPLAINED: Find out what a circuit is composed of and the various types of circuits.  VOLTAGE, CURRENT & RESISTANCE EXPLAINED: Learn the three basic measurements in electronics and what they really mean.  OHMS LAW EXPLAINED: Please learn this one well. It is the basis of electronics. Your future learning depends on you knowing this one inside and out.  OHM'S CALCULATOR: Simple Javascript Ohm's Calculator to help you determine circuit values. RESISTOR COLOR CODES: Simple primer to help answer your basic resistor questions.  RESISTOR COLOR CALCULATOR: This is a COOL javascript resistor color codes calculator - even has a graphic of a resistor with adjustable color bands. Thanks to Danny Goodman for this treat.  UNDERSTANDING AND CALCULATING SERIES, PARALLEL & COMBINATION CIRCUITS These are the basic rules and calculations for series, parallel and combination circuits -- Just as important to learn well as Ohm's Law.  SCHEMATIC SYMBOLS: A list of common schematical symbols used in electronics.