I find that it is most similar to freeBSD jails. Type a command to spin up a container and its just like having a linux VM I can SSH into. With its own file system and everything.
That is a fair statement; however, the capabilities go way beyond those of FreeBSD jails. Lxc/lxd has UID/GID remapping, separate namespaces for container PIDs and the like, the option of unprivileged containers, and cgroups to organize resources.