SSH is installed but not enabled by default in Raspberry Pi OS. It could easily be enabled using raspi-config utility.

Steps to enable SSH server on Raspberry Pi (Raspberry Pi OS):

  1. Open Raspberry Pi Software Configuration Tool (raspi-config) from the terminal.

    sudo raspi-config

  2. Select Interfacing Options from the main interface.
  3. Choose P2 SSH in the Interfacing Options menu
  4. Select Yes to enable SSH.
  5. SSH server is now enabled.