Resume parsing is the step that turns a document meant for a human into data a system can use. A resume arrives as a PDF or a Word file in whatever layout the candidate chose, and parsing reads it and extracts the structured pieces: name, contact details, skills, job titles, employers, dates, education and a short summary. The result is that every applicant, however differently they formatted their CV, lands in your system in the same comparable shape.
This matters because comparison is the whole basis of fair hiring, and you cannot compare documents, only data. Without parsing, someone has to read each application and retype the important parts into a form before any sorting or searching can happen, which is slow and error-prone. With good parsing, that work disappears and happens accurately in seconds.
Parsing is also the quiet foundation that everything else depends on. Screening, ranking and search all read the parsed data, so when parsing is sloppy the errors travel downstream, turning a misread date into a career gap that was never there. Reliable parsing is unglamorous and essential in equal measure.