The ROUGE metric is a widely used evaluation metric for summarization tasks, offering a breakthrough that transformed subjective assessment into quantifiable data. It bridges the gap between machine output and human expectation by evaluating overlapping text elements to measure alignment between machine-generated summaries and human-written references. The ROUGE Metric relies on n-gram matching, calculating recall, precision, and F1 scores to assess how well a generated summary follows the structural flow of the reference. Various ROUGE variants, such as ROUGE-N, ROUGE-L, and ROUGE-S, have been developed to capture specific aspects of summary quality, including word-level similarity, sequence alignment, and flexibility in phrasing. Implementing ROUGE in real-world applications requires careful attention to preprocessing, calculation, and integration into the evaluation pipeline. Several Python libraries make ROUGE implementation straightforward, offering a clean API for calculating various ROUGE metrics. To evaluate AI-generated summaries effectively, teams should consider using comprehensive LLM monitoring solutions and observability best practices alongside ROUGE, as it may not capture deeper semantics or nuances in phrasing.