The Erdős number is a way to describe the "collaborative distance" between a person and the renowned Hungarian mathematician Paul Erdős. If someone co-authors a paper with Erdős, their Erdős number is 1. If they co-author with someone who has an Erdős number of 1, their number is 2, and so on. This concept highlights the interconnectedness of researchers in the field of mathematics. It serves as a fun metric to measure collaboration and influence within the academic community, showcasing how ideas and research spread among mathematicians and scientists.