Here's Why Docker Images Start With "FROM ubuntu"

1 · Andrew Ray · Oct. 25, 2021, 12:45 a.m.
In Docker, we run processes in isolated environments, such as Rails applications or Node.js applications. Why, then, do Docker "image" files start with lines like FROM ubuntu? Are containers running full Ubuntu operating systems? If not, why do we specify an entire operating system? For that matter, what does...