The interface name of a network device increases if the mac address of the physical or virtual network card changes. A common case is if you made a clone of a virtual machine for example via VMware or KVM or replaced a physical network card in a non virtualized server …

In Linux you can add additional network IP's to a network interface with aliases.

Your first interface name looks something like etho. If you add more additional addresses your alias will look some thing like eth0:0 for the first one and eht0:1 for the second and so on …