What is the essence of the GC generations concept (0, 1, 2)? What do we optimize?

The concept of generations in the garbage collector (GC) is based on the observation that most objects in memory have a short lifespan. Memory is divided into generations:

• Generation 0 (young): new objects are placed here. GC checks it most frequently because objects here become obsolete quickly.
• Generation 1 (intermediate): objects that have survived the collection of generation 0 are moved here.
• Generation 2 (old): objects that live long are placed here. GC for this generation runs less frequently.

The optimization lies in checking young objects more often, where the probability of freeing memory is higher, and checking old objects less frequently, which reduces overhead on garbage collection and improves application performance.