When setting up your computer for a network you must first have an IP address which typically is the 192.168.1.100 is the beginning of a dynamic range for your home router network.
This means your first computer and other devices will corresponded to this IP address 192.168.1.100 by your DHCP which mean (Dynamic Host Configuration Protocal). With dynamic addressing other devices can have a individual discrete IP address every time you connect to your network, in some network devices your 192.168.1.100 which is your IP address will change when you are still connected to the network.
This will also support the mix of static and dynamic IP addresses. Dynamic addressing simplifies your network and keep track of your 192.168.1.100 IP addresses rather than a administrator running it. You can add a new computer, laptop, tablet, smartphone without the hassle of a unique IP address for the network.
You can also change your router DHCP range in its configuration utility to use or not use your 192.168.1.100 IP address, this is a private IP address that you assign to your computer to your local network. Try to void dissension, do not use IP address as a static IP address if part of your router’s DHCP range.