What is the purpose of the c flag in the “conda install” command

-c stands for --channel.
It’s used to specify a channel where to search for your package, the channel is often named owner.

The generic command is: conda install -c CHANNEL_NAME PACKAGE_NAME

For example, let’s say you want to download pytorch. You can search on anaconda.org. You’ll see that pytorch (the pacakge) is owned by pytorch.

Then, you’ll just have to do a:

conda install -c pytorch pytorch