Introduction to Real analysis I have a somewhat difficult time understanding this line. Can someone please explain a little bit about this?
A ball of radius $\varepsilon$ around $x$ in $\mathbb{R}$ is a set deﬁned by: $$B_\varepsilon(x) = \{y \in \mathbb{R} : |x−y|&lt; \varepsilon\}$$ 

Thanks for everyone
... and therefore
$$
B_\epsilon(x) = (x-\epsilon,x+\epsilon),
$$
since $|x-y|&lt;\epsilon$ is equivalent to $x-\epsilon&lt;y&lt;x+\epsilon$.
in this case we talk about two distinct point (x,y) in R  |x−y|&lt;ϵ say, ϵ always greater than distance of x &amp; y. this can be easily understand in geometric representation