Absolute elevation (ʿuluww muṭlaq) consists of a relatively short route whose endpoint is the Prophet ﷺ himself. It is compared with another route to the same endpoint that contains more intermediaries.
Example: If an independent route from a transmitter to the Prophet contains eight narrators and another contains ten, the first is shorter in the absolute sense, provided the comparison is made on a consistent basis.
Important qualification: A short and authentic chain combines two virtues; an unreliable shorter route does not overcome its weakness merely by having fewer names.