The "impact factor" is a measure used to evaluate the importance of a scientific journal. It reflects the average number of citations that articles published in that journal receive over a specific period, usually two years. A higher impact factor indicates that the journal's articles are frequently cited, suggesting that they are influential in their field. Researchers often consider the impact factor when deciding where to publish their work. Journals with high impact factors, like Nature or Science, are seen as prestigious, which can enhance a researcher's reputation. However, it's important to remember that impact factors vary by discipline and should not be the sole criterion for assessing research quality.