What’s the difference between slim and tailored fit?

In principle, slim sits closest to the body, tailored (or "classic") is a touch roomier through the chest and waist, and relaxed is loose. In practice, these words are brand-relative — one label’s "slim" is another’s "tailored," because nothing standardizes them. That is why we anchor fit to the published measurements (chest, waist, sleeve, leg opening) and to broad user consensus on whether a piece runs large or small, labeled as consensus rather than our own wear-testing. Treat the fit name as a rough starting point and the size chart as the truth. When both are given, believe the numbers.