# Two kinds of infinity

Just image a line\(x-axis\), go through to the left with no end is $$-\infty$$ \(`negative infinity`\), go through to the right with no end is $$+\infty$$ \(`positive infinity`\), they both are $$\infty$$ \(`infinity`\).

On the contrary, in the opposite of $$\infty$$ is $$0$$.

