What Happens When You Update an SSD?

Updating an SSD involves a series of steps: the controller finds a new block and writes the data there, invalidates the old data, and changes the pointer in the OS to the new physical location. This process prevents overwriting existing data by moving the updated data to a new place each time, resulting in active and invalid data coexisting. Continuous updates lead to filling up the SSD quickly with stale invalid pages, necessitating a costly operation known as garbage collection to clear the invalid data and erase the erasable unit for new data to be written.