Garbage collection
Also called: GC
The runtime periodically finds objects nothing can reach any more and frees them for you.
Definition
The JVM and Android runtime use a garbage collector (GC). Instead of counting references, it starts from live roots (threads, static fields) and frees everything it can't reach, so reference cycles are not a problem. The cost is that collection happens at times you don't control, which can cause short pauses.
In practice
A Spring service creates thousands of short-lived DTOs per request; the GC cleans them up in the young generation without you writing any cleanup code.
Learn it in context
Lessons that use this term.