A shortlist is usually built after screening, once applicants have been checked against the role's requirements. Its size depends on the role, but it is normally small enough for the hiring manager to interview everyone on it within a reasonable time. A good shortlist comes with notes on why each person is included, such as how they meet the must-have criteria and where questions remain.
The shortlist is where screening hands over to the hiring manager, so its quality shapes everything after it. A list built on consistent, job-relevant evidence is easier to trust and to defend than one based on gut feel. When screening at volume, a ranked list helps prioritise attention, but the recruiter still reviews it and decides who goes forward, including people the ranking placed lower.