What's the difference between runtime and devel docker

devel docker (contains the entire SDK along with a development environment for building DeepStream applications)

DeepStream samples docker (contains the runtime libraries, GStreamer plugins, reference applications and sample streams, models and configs)
1、what’s the difference between these two things?
2、Why is there such a big difference in size? 14G and 3.21G


Please refer to the introduction of the containers in DeepStream | NVIDIA NGC