An open circuit occurs when a circuit opens from two points. A short circuit occurs when two parts or portions of the circuit are connected via low resistance path.
Resistance: An open circuit has an infinite amount of resistance, while a short circuit posses zero resistance. Practical short have a small resistance.
Current: The current through any circuit depends on the path. An open circuit has no closed path, thus no current flows through it. While a short circuit has an infinite amount of current. Basic Ohm’s law equation serves as a perfect source to understand this current. As per Ohm’s law: I = V/R,
Now In Open circuit I = V/Infinity = 0
While in short: I = V/0 = Infinity
A disconnected wire in the plug is an example of the practical open circuit.
The broken insulation of two conductors in an extension which is shorted together comprise a short circuit.