Is a postgres index updated automatically?

Question

In my pgAdmin 3 I have a option in the context menu on index that says update. Does this mean an index is not updated automatically on every insert? If that is the case, how can I configure it to update itself?

Answer 1

Indexes are updated automatically as documented in the manual

Once an index is created, no further intervention is required: the system will update the index when the table is modified

As I don't use pgAdmin, I don't know what that "Update" item is supposed to do.