Why is the Human Genome project called a mega project ?

Human genome project was considered to be a mega project because it had a specific goal to sequence every base pair present in the human genome. It took around $13$ years for its completion and got accomplished in year $2006$ It was a large scale project, which aimed at developing new technology and generating new information in the field of genomic studies. As a result of it, several new areas and avenues have opened up in the field of genetics, biotechnology, and medical sciences. It provided clues regarding the understanding of human biology