What does setting the environment variable GOGC to 100 mean in the context of garbage collection in Go?

The GOGC environment variable in the Go language controls the threshold for triggering the garbage collector (GC) in percentage. A value of 100 means that the garbage collector will run when the allocated heap size increases by 100% compared to the memory size after the last GC run.

In simpler terms, if after the last garbage collection the heap was of size X, the next collection will be triggered when the heap reaches size 2X (i.e., doubles). This is the default value and balances between performance and memory usage.

Changing GOGC affects the frequency and intensity of garbage collections: a lower value results in more frequent collections and less memory consumption, while a higher value results in less frequent collections but greater memory usage.