Your bot token is a very crucial piece of information. It must be protected from being leaked at all cost, otherwise a malicious actor may use it to perform disruptive actions as your bot.
An env file is used to store environment variables, which are kept separate for the rest of the code. They are ideal to store tokens, API keys and other kind of sensitive information. Python does not support them natively, so we're going to install a package to make use of them. Type this command in your terminal:
pip install python-dotenv