Engineers design their initial products using schematic symbols that can be confusing to the novice or non engineer. Below are the major symbols used and what they mean.

These are just some of the common symbols used in electronics. Wikipedia has a more detailed list here.

Looking at some specific symbols used in electronics, the ones below cover many of the major symbols of component types.

Wire Symbols

Power Related Symbols

Resistor Symbols

Capacitor Symbols

LED Symbol

Transistor Symbols

Contact Switch Symbols

Microcontroller Symbols

These are the basic symbols, if you use others on a regular basis and want to include please add them in the comments below. Find ome of the lesser ones  not used regularly  here.