Satellites, crewed vehicles, probes — everything launched to do a job. Only a minority are still working: CelesTrak's operational-status column separates a live satellite from a dead one sharing the same orbit.

Spent upper stages. Each one is a tonnes-heavy object left in the orbit it delivered to, often with residual propellant — which is why several have exploded years after launch and become debris clouds of their own.

Fragments: explosions, collisions, and deliberate anti-satellite tests. This is the largest category in the catalogue, and the reason is self-reinforcing — the 1978 Kessler and Cour-Palais result is that above a certain density, collisions generate fragments faster than atmospheric drag removes them, so the population grows without further launches.

collision rate ∝ n² — quadratic in density, which is what makes it run away

Tracked, but not attributed in the public catalogue. Turning these off is turning off the honest admission that the public data is incomplete.