Zend certified PHP/Magento developer

Assigning static ip

I have the following question: I have a raspberry pi with openmediavault running on my network, and I want to assign it a static ip address. However, Im running a DHCP, and here comes my confusion.

DHCP assigns ip’s automatically, and my router allows to assing a static ip while using DHCP with the MAC address of the device. However, I noted that I can also assign the static IP address to the interface. So imagine the case where I assign a static IP to my interface, removing the DHCP in the computer, and I try to connect to my router that has DHCP enabled, would there be any problems? The router will know that the IP of the device is the one in the interface? Could the router assign that static IP to another device?