With LXD as one of the most important features of Ubuntu 16.04 LTS, you might want to read more about it. Stéphane Graber has started a blog post series that will bring you up to speed. In his first post - Introduction to LXD - he answers a few common questions about LXD.
Its main goal is to provide a user experience that’s similar to that of virtual machines but using Linux containers rather than hardware virtualization.
LXD focuses on system containers, also called infrastructure containers. That is, a LXD container runs a full Linux system, exactly as it would be when run on metal or in a VM.
In contrast, Docker focuses on ephemeral, stateless, minimal containers that won’t typically get upgraded or re-configured but instead just be replaced entirely. That makes Docker and similar projects much closer to a software distribution mechanism than a machine management tool.
— Stéphane Graber
Continue reading his blog post series about LXD 2.0 or even try LXD online.