A sales plan lays out your objectives, high-level tactics, target audience, and potential obstacles. It's like a traditional business plan but focuses specifically on your sales strategy. A business plan lays out your goals — a sales plan describes how you'll make those happen.
Sales plans often include information about the business's target customers, revenue goals, team structure, and strategies and resources necessary to achieve its targets.
One thing to keep in mind, though, is that sales planning doesn't just encompass the creation of a sales plan document. A high-level strategy is required for that document to be more than something that gathers dust on the bookshelf.