What is the difference between lxc and lxd?

Question

LXC

Updated Ubuntu from 14.04 to 16.04 on my home machine. Before that, I used LXC containerization, but now, everywhere on the Internet they write that LXD support
is finally included in Ubuntu 16.04. The question is, how do they differ from each other? As far as I understood correctly, LXD is an add-on to LXC, but what exactly does this mean? The second question: What, in this case, to use after updating the system? LXC, after the update, picked up all the containers that were created and worked on Ubuntu 14.04. Is it necessary to install LXD on top as well?

Answer 1

It seems to be clearly described . Not?

Answer 2

In short, LXD is a daemon that runs on top of LXC and provides a REST API for working with LXC containers. In other words, a more understandable and unified "language for communicating with LXC containers".
The configuration files that were used to set up containers when using pure LXC are not applicable to configuring containers using LXD.
The configuration of containers that are created using LXD is carried out using this most unified "language for communicating with LXC containers".
These are the first conclusions that we managed to draw after updating the operating system and installing LXD.
This brings me to the next question.