Countably zero-dimensional space
From HandWiki
A normal space $X$ that can be represented in the form of a union $X=\bigcup_{i=1}^{\infty}X_i$ of subspaces $X_i$ of dimension $\dim X_i\leq 0$.
Comments
If $X$ is a metrizable space, then its countable zero-dimensionality is equivalent to it being countable dimensional, i.e. being the union of countably many finite-dimensional subspaces.
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