What is severity vs priority? Definition for bug triage

Severity is how bad a bug is when it happens; priority is how soon the team will fix it. They are different because not every severe bug is urgent, and not every urgent bug is severe.

The distinction prevents two failure modes. The first is treating every showstopper as also-fix-tomorrow when the showstopper hits two users a year — high severity, low priority, fix when it bubbles up. The second is treating cosmetic problems as low-effort optional work when they are visible on the homepage — low severity, high priority, fix today.

The usual scales

Severity typically runs from cosmetic to crash, often with four to five levels. Priority typically runs from "next release" to "immediate hotfix," often with three to four. Different organizations use different labels (S1–S4, P0–P3, blocker / critical / major / minor), and what matters is that both axes exist and are set deliberately.

A bug report that includes both, with one sentence justifying each, makes triage cheaper for everyone downstream. The PM and engineer do not have to guess what the reporter meant; the visible severity is recorded with the artifact and the priority is the team's call against the rest of the queue.