Figure 1 shows this internet. First, you see three separate Ethernet segments, three separate subnets.
Ovals represent two of the networks.
The left oval, containing 199.100.200.0, is shorthand for an Ethernet with up to 254 computers. Addresses range from 199.100.200.1 through 199.100.200.254. I said 254, not 253, because these subnets have no default gateway. Between these ovals is a third subnet, with the address 210.50.200.0. The PC in the middle contains only one Ethernet card, and its IP address is 210.50.200.40.