The Hadamard Gate is Underrated
The fundamental unit of information in regards to a classical computer is called a bit. Bits can be described either as a 1 or a 0 (on and off respectively). However quantum computers use qubits. A good way to distinguish the two is the glass metaphor. Bits can be one of two things: a full glass or an empty glass. Qubits can be anywhere in between. So, just like classical bits, qubits can be in one of the two states 0 or 1. Bits, however, cannot be in a superposition of the two while qubits can.
In the case of qubits, 0 and 1 are represented in the Dirac notation: