Changed my IPv4 to ssh into OpenWRT on rpi2 - did dhclient on my host afterwards- Now I have two IPv4 on one NIC - and it works! How?

as described in the title, sorry I wanted to have a specific title and I could not get it specific and short and the same time, I did the following: 1. Flashed a SD Card with OpenWRT to test it on a Raspberry Pi. 2. OpenWRT has dhcp client disabled and puts a static IP in that image that does not correspond to my network IPv4 pattern. 3. So I changed my host IPv4 to 192.168.1.2 in order to connect to 192.168.1.1. That worked. 4. After logout I did dhclient on my host. Now I have access to all my network devices as before and still can connect to that OpenWRT machine I described above. I only have one NIC on my host system. So I wonder how this can work?

1: lo:  mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether *somevalue* brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.2/24 brd 192.168.1.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 10.88.88.80/24 brd 10.88.88.255 scope global dynamic eth0
       valid_lft 863229sec preferred_lft 863229sec
    inet6 XXX/64 scope global dynamic mngtmpaddr 
       valid_lft forever preferred_lft forever
    inet6 XXX/64 scope global dynamic mngtmpaddr 
       valid_lft 7013sec preferred_lft 1613sec
    inet6 XXX/64 scope link 
       valid_lft forever preferred_lft forever