(General Question) What is Garbage Collection?

SSD controllers use a technique called garbage collection to free up previously written blocks. This process also consolidates pages by moving and rewriting pages from multiple blocks to fill up new ones. The old blocks are then erased to provide storage space for new data. However, since flash blocks can only be written to so many times before failing, it is important to also wear-level the entire SSD to avoid wearing out any one block prematurely.