| Origin | Predefined by Python | User-defined by programmer |
| Purpose | Define program structure, control flow, data types, operations | Label variables, functions, classes, modules |
| Usage | Fixed meaning and functionality | Descriptive names reflecting code purpose |
| Flexibility | Cannot be changed or used for other purposes | Can be chosen by programmer within naming conventions |
| Case Sensitivity | Yes (if != If) | Yes (myVariable != MyVariable) |
| Examples | if, else, for, while, def, class, True, False | name, calculate_area, my_list, student_class |
