End-to-End (E2E) describes a process that takes a system or service from beginning to end and delivers a complete functional solution, usually without needing to obtain anything from a third party. It often refers to vendors that can see a project through from beginning to end, and supply everything needed to create a workable solution—be it hardware, software, labor, written materials, and procedures. End-to-end solutions also adhere to a philosophy that eliminates as many middle layers or steps as possible, which helps to optimize the performance and efficiency of a business.