I suppose I’m being a little harsh, I just deal in networks and it made me pause but I forget not everyone knows what I know. I apologize for being rude.
Essentially your internal private network operates on three ranges of numbers depending on your specific needs. Homes usually never need more than a couple dozen but even the most advanced home network probably only uses half a dozen subnets at most and need fewer than 253 devices per, so usually you get 192.168.0.0-192.168.255.255/24 because it’s more than enough. The “/24” denotes (out of 32) where the subnet ends, essentially how we are dividing up the allotted space in the IP scheme we are given. The “Class C” range (mentioned above) has an available 65,000+ addresses. Usually more than enough for any way you want to slice it up. Mostly you’ll just see people sling /24’s around because it’s an even interval of 1 in the last octet which makes things simpler.
People who build more robust “networks” (in the commercial sense) at their houses will usually operate a few different ones, some for internal and others set aside in “DMZ” zones for outward facing servers. Such as gaming servers or self hosting jellyfin!