In most CRM systems, the term deal designates an opportunity to sell your products or services. Some systems use the term opportunity instead of the deal. The process of working with deals is called deal or opportunity management.
Deals typically come with custom deal stages, which are used to visualize sales pipeline and to estimate future revenues. The final deal (opportunity) stage is closed (won) or closed (lost).
Advanced CRM systems let you create quotes and invoices directly from deals and accept online payments. They also usually allow you to automate deal management by automatically creating tasks, alerts or sending emails to clients when a deal changes its stage.