Simple definition
A floating static route has a higher administrative distance than the preferred route and becomes active when the primary route disappears.
Purpose and use
A floating static route prepares a backup path with less favorable administrative preference than the primary route to the same prefix.
How does it work?
The router selects it only when routing-table rules allow its use, typically after the preferred route disappears.
Example and verification
Validate the backup by observing the routing table and testing forwarding after loss of the link or monitored target.
Points to watch
A link can remain physically up while a remote destination is unreachable. Without suitable tracking, the primary route may remain installed.
In short
Administrative preference compares eligible route sources; a more-specific route can still take priority through longest-prefix matching.