The PM Glossary: Terms Everyone Assumes You Already Know

Nobody hands you a glossary on day one. You’re expected to nod along when someone says “what’s on the RAID log” or “who’s the R on the RACI for this.” Here’s what the core terms actually mean, without the textbook phrasing.

RAID log

Risks, Assumptions, Issues, Dependencies. One running document that answers: what could go wrong (risks), what are we taking on faith (assumptions), what has already gone wrong (issues), and what are we waiting on from someone else (dependencies). If a project has no RAID log, it has all of these problems anyway — they’re just untracked.

RACI matrix

A table that assigns, for each decision or task: who is Responsible (does the work), Accountable (owns the outcome, signs it off), Consulted (gives input beforehand), and Informed (told after the fact). Most project confusion traces back to two people both assuming they were “A” — or nobody realising they were.

WBS (Work Breakdown Structure)

A hierarchical breakdown of a project into smaller and smaller pieces of work, until each piece is small enough to estimate and assign to one person or team. Think of it as the project’s table of contents, several levels deep.

Baseline

The original approved version of your scope, schedule, and budget — frozen at a point in time so you can measure drift. “We’re two weeks behind baseline” only means something if you know what the baseline was.

Critical path

The longest sequence of dependent tasks in your schedule — the one that determines your minimum possible finish date. Tasks not on the critical path have “float” (slack); tasks on it have none. Delay any task on the critical path and the whole project slips.

Milestone

A zero-duration marker for a significant point in the project — not a task itself, but a checkpoint (“Phase 1 sign-off,” “UAT complete”). Milestones are how you communicate progress to people who don’t want the full task list.

RAG status

Red/Amber/Green — a simple visual shorthand for reporting health at a glance. Green: on track. Amber: at risk, needs attention. Red: off track, needs escalation. The RAG colours on this site’s tags borrow directly from this convention.

Keep this list open in a tab for your first few weeks. The jargon stops being intimidating once you realise it’s mostly just names for things you’d naturally want to track anyway.