Marketing Plan: In this you perform, precise activities which helps in achieving the goals and objectives you are targeting at. Here, you plan how you will promote the product/service? What are the specific areas of promotion? What would be the budget of this plan execution? Etc. Plus, you also estimate the ROI of this marketing strategy.
To make an effective plan, there is a famous rule called 4P's. Here, P's stand for Price, Product, Promotion and Placement. In this another P is added called People. Today while doing digital marketing or the traditional marketing one should understand people or the customers you are dealing with. It's important to figure out what is significant for the business, and later make a plan accordingly.