# What is a logic circuit?

A **Logic circuit** uses two logic levels to transfer the information. A high logic level or “1” and a low logic level or “0”. The Logic circuits are made of digital elements such as the AND gate, the OR gate, the NOT gate and combinations of them.

These combinations give way to other types of digital elements, such as logic gates, among others.

– NAND gate

– NOR gate

– Exclusive OR gate

– Mutiplexors

– Demultiplexors

– Decoders

– Encoders

– Memories

– Flip-flops

– Microprocessors

– Microcontrollers

– Etc.

Modern digital electronics is used to perform many functions. While digital electronic circuits might seem very complex, actually they are built with a very large number of very simple circuits.

In Digital electronics the information is transmitted between circuits in a binary form (zeros and ones). The binary information is represented in the form of:

- “0” and “1”,
- “Open” or “Closed” (switch)
- “On” and “Off”
- “False” or “True”, etc.

A** logic circuit** can be represented in many ways. In the following circuits, the lamp can be turned on or off, depending on the switch position.

A truth table is a tabular listing of all possible states of the switches (inputs) that affect the circuit and their corresponding output values.