Conda is a package management and environment management system
Virtualenv is a tool that creates sandboxed Python environments.
Anaconda alternative packages
"If you are using anaconda conda is a better alternative to virtualenv as it manages conda packages which are not limited to just python packages"
from question "How to handle with different pythons in the computer"
"An additional bonus i find that conda works better as a package manager than virtualenv"
from question "Error installing numpy"