Meaning of "within a constant factor from"?

Question

When a quantity $A$ is said to be "within a constant factor from" another quantity $B$,

• does it mean that there exists a posiitve constant $C$, so that $A \leq C B$?

• does it assume $A$ and $B$ both are nonnegative?

Thanks.

Answer 1

It generally means that $\frac{A}B$ remains in some interval $(c,C)$ for $0<c<C$.