Running accession ID for the same experiment

Question

[sophialovechan]

Hi everyone, I am trying download some RNA-seq data from GEO. So for each sample, there are two SRR numbers (running accession ID). For example, sample Donor9605, the running accession numbers are SRR3745558 and SRR3745559. The sizes of fastq. files from these two SRA are the same. I don't understand what the difference is. My first thought would be they are two different files for pair-end sequencing. But I found they are single-end sequencing data. Would anyone help me with this? Thank you.