SSH or Secure Shell Access is way to run commands on your Raspberry pi using your PC or Laptop. We connect the Raspberry pi to PC or laptop using an ethernet cable or wifi and then ssh using the IP address of the Raspberry pi. If you don't know how to SSH into the Raspberry pi, here is a tutorial on how to do it.
[sudo] apt-get update
git clone https://github.com/rishabhio/iotbeginner.git
[sudo] python app.py