是定语从句。where引导的定语从句和状语从句区别是,定语从句中where之前有先行词,where可以替换成介词(in、on、of...)+关系代词(which、that...)。而在状语从句中,where不可以替换,替换之后就没办法翻译,说不通过了。举个例子Make marks where you have any problems.(状语从句),你看where前面是个动词,不是先行词。如果把where还成in which那么which就没有指代对象了。Make marks at the places where you have any problems.(定语从句)有先行词place。你的那句话中a system就是先行词,where可以替换成in which
定语从句,这里的where=in which,由此看出是定语从句。
where是可以作为定语从句的关系副词的,关系副词:在句中作状语 ,关系副词=介词+关系代词(which之类的),可以如上替换的就是where引导的定语从句,看这个You should have put the book where you found it.是where引导的状语从句,就不能做如此替换,只能这样You should have put the book on the bookshelf where(on which) you found it
是状语从句,因为where引导地点状语