Opportunities are the sales and pending deals that you want to track. By adding opportunities within Salesforce, you are contributing to your sales forecast. Similarly, a sales person can create quotes to offer a customer different combinations of plans and prices.
You can create an opportunity or quote by following the steps in this article. Once you have created your opportunity or quote, the same setup steps, such as billing options, coupons, and contracts, apply to both and can be edited at any time.