packages installed after activating conda environment

Question

I want to know after creating and activating a conda environment in terminal. Say venv:

conda create -n venv
source activate venv

Then the prompt will come with the enviroment name (venv).
would the packages installed (say conda install tensorflow without --name venv) after environment activation only effect inside the environment venv? Or would it affect outside venv?
I don't want to mess up my environments.