Variable names in Python must follow these rules: Start with a letter or underscore, not a number. score1 is valid, 1score is not.
Contain only letters, numbers, and shows. No spaces or special characters.
Case matters. Name, name, and NAME are three different variables.
Don't use Python's reserved words like if, for, while, class, def. Convention: use lowercase with shows for multiple words: user_name, total_score, is_valid. This style is called snake_case and is standard in Python.