Communication Is a Two-Way Process but is just a complex process if you think it to be merely enough to deliver a massage. That you can call simple communication.
As speakers, we sometimes focus exclusively on the information that we want to relay. But your listener or reader may understand your message, only a portion of it, or miss your point entirely—even though you transmitted the information accurately by your standard It is very important that the message must be received well for communication to be successful. When your listener/reader(target audience) is a group of people covering the young, the elderly, the low-income, various ethnic groups, communication becomes not only challenging but also extremely difficult.
An effective communication is one that sends the message efficiently and elicits the desired response accurately.