NAS is often a single device made up of redundant storage containers or a redundant array of independent disks (RAID). SAN storage can be a network of multiple devices of various types, including SSD and flash storage, hybrid storage, hybrid cloud storage, backup software and appliances, and cloud storage. Here are how NAS and SAN differ: Backup storage and appliances protect data loss from disaster, failure or fraud. They make periodic data and application copies to a separate, secondary device and then use those copies for disaster recovery. Backup appliances range from HDDs and SSDs to tape drives to servers, but backup storage can also be offered as a service, also known as backup-as-a-service (BaaS). Like most as-a-service solutions, BaaS provides a low-cost option to protect data, saving it in a remote location with scalability. This popular model can operate a wide variety of appliances, including a furnace, fridge, microwave, most 13,500 BTU RV AC units, and much more. Take a look at the applications tab for more examples. There is no gold standard for ACL reconstruction. Each surgeon has a different technique and preference. More recent techniques are showing outcomes that are still inconclusive for long term results . Different techniques include arthroscopic vs open surgery, intra vs extra-articular reconstruction, femoral tunnel placement, number of graft strands, single vs double bundle and fixation methods.  Extra-articular reconstruction has been used to address pivotal shift which has been shown to have greater effects than that provided by intra-articular reconstruction, but lacks residual stability. Intra-articular became the method of choice, but it doesn't restore the normal knee kinematics. Double bundle is considered more anatomical and supportive especially during rotary loading. It is able to reproduce anteriomedial and posteriolateral bundles using gracilis and semitendonosis tendons.