The lead author is the first named author of a publication - i.e. a research article or audit. The lead author is typically the person who carried out the majority of the research, and wrote and edited most of the manuscript. The list of trailing co-authors reflects, typically, diminishing contributions to the work reported in the manuscript.
Authorship standards vary widely across disciplines [1]. The proportion of multi-author papers has increased in recent decades, reflecting increasingly complex multi-investigator research projects [2], as well as the "publish or perish" culture of academic performance evaluation.