"Not clear what this means?"

Show solution Note that our description of Hasse diagrams made use of the covers relation $\\prec$\. The covers relation, however, is not a helpful in many posets\. Consider the poset $\\langle \\mathbb R, \\leq \\rangle$ of the real numbers ordered by the standard comparison $\\leq$\. We have $0 < 1$, but how would we convey that with a Hasse diagram? The problem is that $0$ has no covers, even though it is not a maximal element in $\\mathbb R$\. In fact, for any $x \\in \\mathbb R$ such that $x > 0$, we can find a $y \\in \\mathbb R$ such that $0 < y < x$\. This "infinite density" of $\\mathbb R$ makes it impossible to depict using a Hasse diagram\.

Not clear what this means?