This study explores the global virome by analyzing over 5 terabytes of metagenomic sequence data from 3,042 diverse samples. The researchers identified over 125,000 partial DNA viral genomes, including the largest phage ever discovered, and increased the number of known viral genes by 16-fold. They found that half of the predicted partial viral genomes clustered into genetically distinct groups, most of which included genes unrelated to those in known viruses. Using CRISPR spacers and transfer RNA matches, they doubled the number of microbial phyla known to be infected by viruses and identified viruses that can infect organisms from different phyla. The analysis revealed strong habitat-type specificity for most viruses but also identified some cosmopolitan groups. The results highlight extensive global viral diversity and provide insights into viral habitat distribution and host-virus interactions.This study explores the global virome by analyzing over 5 terabytes of metagenomic sequence data from 3,042 diverse samples. The researchers identified over 125,000 partial DNA viral genomes, including the largest phage ever discovered, and increased the number of known viral genes by 16-fold. They found that half of the predicted partial viral genomes clustered into genetically distinct groups, most of which included genes unrelated to those in known viruses. Using CRISPR spacers and transfer RNA matches, they doubled the number of microbial phyla known to be infected by viruses and identified viruses that can infect organisms from different phyla. The analysis revealed strong habitat-type specificity for most viruses but also identified some cosmopolitan groups. The results highlight extensive global viral diversity and provide insights into viral habitat distribution and host-virus interactions.