Router
Specialized Device for exchanging data amongst class based Networks & Subnetted (multiple parts of one network) is Router.
A switch box
The network device that connect multiple networks that use the same protocol is a ROUTER.
Active scanning transmits a probe frame, which is a process used by a device to search for available networks by broadcasting a wireless signal and waiting for responses from nearby access points. This allows the device to discover and connect to available networks in its vicinity.
Hierarchically designed networks can more easily be expanded to suit future needs.Hierarchical design models enhance existing bandwidth through the use of link aggregation.The hierarchical model allows for specialized functionality at each layer, simplifying device management
To download multiple photos from Flickr, you can create an album or select multiple photos and then use the download option provided by Flickr. This allows you to easily save multiple photos to your device at once.
The internet anywhere device works by connecting to cellular networks or satellite signals to provide internet access in remote areas. Its key features include portability, compatibility with multiple devices, and the ability to access the internet without relying on traditional Wi-Fi networks.
Though this question is pretty ambiguous, you probably mean NBMA networks (Non-Broadcast Multiple Access).
hub
Router
A speaker selector can be used with one or more amplifiers. Multiple speakers can be used by connecting into a speaker selector. It allows a radio or outlet device to be played on multiple sources.
Connecting different networks requires a router