Photosynthesis, for example, is a way that plants take energy from the abiotic environment and incorporate it into the biotic environment by synthesizing sugars and proteins from it. Other components of the biotic environment, such as herbivores, eat the plants and transfer the nutrients further along the chain.
Source: Adaptec. Backplanes are the fundamental building block to any storage appliance that is meant to support hot plugging. So, SAS expanders will always go hand in hand with powerful backplanes (whether these are in a single box or not).
Techopedia explains Back-End System. The separation of front-end and back-end computer systems simplifies the computing process when dealing with multilayered development and maintenance. Back-end systems deal with databases and data processing components, so the purpose of the back-end system is to launch the operating system's programs in response to front-end system requests and operations. In other words, the back-end system implements responses to what the front end has initiated.