Here are three different approaches you can use to move from using dynamic IPs, handed out by DHCP, to configuring static or permanent addresses:
Reserve DHCP addresses on the router for select clients: If your router has a DHCP reservation feature, this is a great way to quickly solve your IP dilemma. You don't have to physically configure each computer. You simply tell the router to always give a client a certain IP.
Thus when the client polls the DHCP server when it connects to the network, it will automatically receive its reserved IP. Clients without a reservation will simply receive a random IP like normal. You might even think about doing this for all your computers and devices; it's quick and easy.
Manually configure select clients with static IP addresses: Do this only if select devices and computers need a static IP and the other ones can use DHCP. You'd have to take a minute or two and input the IP details into the desired computer(s). It's not as quick to go this route with multiple computers; however, you don't have to access the router.
Even regular network users have the ability to do this, given that they have administrative rights on their Windows account or at least the ability to edit network settings.
Manually configure all clients and disable DHCP on the router: This is similar to the above approach but requires you or the users to manually configure any device that connects to the network.
This is great if you find it beneficial that all the computers and devices have a permanent IP address. Just keep in mind that you'll need to manage these addresses.
If you have more than a few clients on the network, you'll probably have to store a list of addresses and reference it when new clients join, so there isn't a conflict.
We'll step through these approaches in the next sections
In Simple words for static we define the ip address manually under the interface.
ip address 18.104.22.168 255.255.255.0 <<< This means you are statically defining the ip address to the interface.
*Set to an IP address which is unchanged for months or years at a time. This is a static IP address