What does static DHCP mean? Static Dynamic is confusing

A DHCP reservation. Cisco refers to it as "Static DHCP".

More information here. (CTRL-F for "static allocation").

You're talking about a DHCP reservation. This is actually a common feature but little-known by most folks. It's quite useful for locking an IP address to a machine, but wanting to keep centralized control over its settings for DNS and default gateway, etc. Very useful.

My router calls it IP-MAC binding

Also heard it refered to as DCHP reservation