The Various Uses of SD-WAN Software-defined networking in a wide area of network which is shortened as SD-WAN, is basically one of the products produced by the internet and computer which are recognized as the two most important technologies of all time, and its basic function is to simplify the operation and the management of a WAN or wide area network by decoupling or separating the mechanism of control of a network hardware. The designers and inventors of this certain product aims to help the business companies who wants to replace wholly or partially their expensive private wide area network connection technologies with a lower cost leased lines, and that is by allowing them to build a much higher performance of WAN. The various benefits which a business company can gain from using such great modernized products includes the chance and the privilege of delivering the services and applications required to perform business functions, to connect remote branch offices to data centers and the privilege of extending their computer networks over larger distances. SD-WAN are designed by its manufacturers and inventors to address network problems and operational challenges like jitter, packet loss, service outage, network congestion, lower latency requirements of modern operations like video conferencing, streaming media, virtualized applications and desktops, and VoIP calling, bandwidth requirements for featuring high-definition video, difficulty and expensive costs of expanding WAN capability and difficulties in management of network and troubleshooting. In using the SD-WAN it enhances and replacing the traditional branch routers by using virtual appliances, and these appliances can control the application-level policies and offer an overlay of the networks with the use of a less-expensive consumer level internet links which acts as a dedicated circuit. An SD-WAN product can be a physical appliance or a virtual appliance and they are commonly placed in small remote offices, branch offices, corporate data centers and cloud platforms. The required characteristics of every SD-WAN products includes the ability of doing dynamic path selection which can be used for resiliency purposes or load sharing, the ability of supporting multiple connection types like frame relay, MPLS or multiprotocol label switching and higher speed LTE or long-term evolution wireless connections, the ability to support VPNs or virtual private network and third party services like WAN optimization controllers, web gateways and firewalls and a simple interface that is very easy to manage and configure. The features offered by these products includes security, quality of service or QoS, flexible deployment options, simplified administration, troubleshooting, and resilience.