A discrete-time signal is a type of signal that is defined only at discrete time instants. In other words, a discrete-time signal is a sequence of numbers, where each number represents the amplitude of the signal at a specific time instant.
The discrete-time signal $x(n)$ is a function of a discrete variable.
$
\forall n \in \mathbb{Z},\; x(n) = \ldots
$
in the form of a [[mathematical function]]:
$
x: \mathbb{Z} \rightarrow \mathbb{R}
$
Where $\mathbb{Z}$ is a [[set of numbers]] that includes all integers.
These signals are often referred to by the abbreviated form of _discrete signals_.
A discrete-time signal can be the result of [[sampling]] a [[continuous-time signal]].