Network interface is almost a like a "network card". Except it's not necessarily a physical card.
This short article tells you what names (like wlp4s and enp1s0) mean.
These are the new names used by Debian and other systemd distros.
Create a new virtual machine in 20 seconds. Install only packages from official, main Debian repositories. Does not need VirtualBox or NFS.
Short version for gurus: apt-get install vagrant vagrant-libvirt. Use vagrant normally, but disable NFS with config.vm.synced_folder ".", "/vagrant", disabled: true.
The rest of us can read on for full background and tutorial...
Start a two computer virtual network in minutes.
Install Debian Linux on VirtualBox. You can play with Linux even on Windows, before you completely move to Linux.
This is a beginner friendly tutorial, with quazillion screenshots.