\begin{tabular}{l} A variable cost is one that changes \\ in the long run only \\ in the short run only \\ year to year \\ month to month \\ \hline as output changes \end{tabular}

Variable costs are like the dance partners of a business's financial waltz; they groove and sway as production levels rise and fall! For instance, if a bakery produces more cakes, the cost of flour, sugar, and eggs increases proportionally. So, the more you bake, the higher those ingredient costs become, reflecting the direct relationship between output and expenses. Imagine you're a chef in a bustling restaurant. When you decide to serve more dishes, your costs for fresh produce and meat will spike, while low output days mean your variable costs drop. Understanding this rhythm is key to keeping your finances balanced and preparing for the highs and lows of business demands!