https://yiweiniu.github.io/blog/2019/03/ATAC-seq...
Ref: Biostars - FRIP score ATAC-seq. In paired-end sequencing, we use the word fragment because the two reads that are produced always originate from the same DNA fragment and are therefore not independent of each other as reads from single-end sequencing would be. As FRiP comes from single-end ChIP-seq data, this is why they probably termed it ...