How to view reciprocal differences more easily

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During my analysis class I have encountered expressions like $\left|\frac{1}{l} - \frac{1}{k}\right| < \text{ some bound }$ multiple times, where we deduce something regarding the values of the positive integers $l$ and $k$. My intuition regarding the reciprocals is limited, and most of the time I would like to expand the fractions to have a common denominator even if it does more harm than good. So, give some $\epsilon > 0$, what would you infer about $l, k$ in the inequality $\left|\frac{1}{l} - \frac{1}{k}\right| < \epsilon $?