Next generation sequencing results in a high number of individual sequences that are typically 30-100 bp long, and it is common to call these sequences for reads.
Datasets needs to be mapped (a.k.a. aligned) to a reference genome before they can be imported into EaSeq, and EaSeq cannot use unmapped reads without coordinates. We have a guide on how to do this here.
During import, the only information used by EaSeq is the genomic coordinate, and other information such as sequence or quality metrics is discarded.