Some communication courses only talk about how to deliver your message/thoughts/ideas in a way that's convincing and that's effective. They cover "tricks" on how to portray one's thoughts in a way that helps you.
For example, if you were working with a communication coach, they may tell you how to change your email or how to approach your communication with your supervisor to minimize conflict or result in a most favorable outcome for you. These however could dangerously lead you to learn various tricks that do give you short-term advantages but wherein the long term, your situation could be significantly compromised.
Learning how to communicate effectively without first internalizing key principles and to have communication simply be a better reflection of who you are, is really what in my mind, effective communication is. In other words, to be effective at communication, you must first become a person with various positive core values.
If you don't build and internalize these core values yourself, knowing how to just communicate well just to gain an advantage for you, will not go a long way for you. You will most likely lose friends, lose support from supervisors, lose promotions, lose recognition that you've earned in the short term if you're NOT the person you portray yourself to be.
Therefore, first, strive to be a person with the positive core values (that will be introduced in this course and which you will also self-discover in your journey) and THEN to learn how to communicate your thoughts/ideas effectively through writing, etc.