On the apt-get man's page, one can find this:
install pkg(s)
This option is followed by one or more packages desired
for installation. Each package is a package name, not a fully
qualified filename (for instance, in a Fedora Core system, glibc would
be the argument provided, not glibc-2.4.8.i686.rpm).
All packages required by the package(s) specified for installation
will also be retrieved and installed.
[...]
build-dep source_pkg
Causes apt-get to install/remove packages in an
attempt to satisfy the build dependencies for a source package.
It sounds like both of those are trying to satisfy dependencies, but I had different results while installing matplotlib
with each of those: apt-get intall
didn't work with my subsequent pip install matplotlib
in my virtualenv, while apt-get build-dep
did*.
*
Yeah, I needed to install matplotlib
in a venv, but pip couldn't resolve some of the dependencies, so I lazily used apt in order to solve it