Graph of the Exponential Function $y = 2^x$

$y = 2^x$ is an exponential function with base $2$; its domain is all real numbers and its range is $y > 0$. Its value doubles each time $x$ increases by $1$.

As $x \to -\infty$ it approaches $0$ (the $x$-axis is an asymptote), and it passes through $1$ at $x = 0$. Since the base is greater than $1$, it increases monotonically.