(N/A) $NOT$ Gate:
Symbol: Shown in figure $(a)$. It has one input $A$ and one output $Y$.
Function: If input is $1$,output is $0$. If input is $0$,output is $1$. It acts as an inverter.
Boolean Equation: $Y = \overline{A}$.
Truth Table:
| Input $A$ | Output $Y$ |
| :--- | :--- |
| $0$ | $1$ |
| $1$ | $0$ |
$OR$ Gate:
Symbol: Shown in figure $(a)$. It has two or more inputs $(A, B)$ and one output $Y$.
Function: The output is $1$ if at least one input is $1$.
Boolean Equation: $Y = A + B$.
Truth Table:
| Input $A$ | Input $B$ | Output $Y$ |
| :--- | :--- | :--- |
| $0$ | $0$ | $0$ |
| $0$ | $1$ | $1$ |
| $1$ | $0$ | $1$ |
| $1$ | $1$ | $1$ |
$AND$ Gate:
Symbol: Shown in figure $(a)$. It has two or more inputs $(A, B)$ and one output $Y$.
Function: The output is $1$ only if both inputs $A$ and $B$ are $1$.
Boolean Equation: $Y = A \bullet B$.
Truth Table:
| Input $A$ | Input $B$ | Output $Y$ |
| :--- | :--- | :--- |
| $0$ | $0$ | $0$ |
| $0$ | $1$ | $0$ |
| $1$ | $0$ | $0$ |
| $1$ | $1$ | $1$ |