What is the name of the process of moving elements from one Map to another?

In Go, there is no special term for the process of moving elements from one map to another. It is usually called "copying" or "transferring" elements. To do this, you need to iterate over the source map and assign values to the target map, then delete the elements from the source if necessary.

Example:

source := map[string]int{"a": 1, "b": 2}
dest := make(map[string]int)

for k, v := range source {
    dest[k] = v
    delete(source, k) // if you want to move rather than copy
}

Thus, elements are "moved" from one map to another through copying and deletion.