Routers play a major role in networks by interconnecting multiple sites within a network and connecting ISPs on the Internet. Basically, routers play role of translator between different media types and protocols. For example, a router accepts packets from a network and transport them over a serial network after encapsulation.
According to the features and applications, routers are divided into three major categories.
Broadband Routers: Broadband routers are used to connect computers/Laptops to connect to the Internet. Broadband router are required when we connect internet through phones. ADSL modems are used for this purpose as they embed both phone and Ethernet jacks.
Wired and Wireless Routers: These days wired and wireless router are most commonly used in the home and small office networking. Wired and wireless router are able to transmit internet signals and maintain routing information in their routing table. They are also capable to filter traffic on IP addresses base.
Edge Router: Edge routers are placed at the edge of the ISP network. These are normally configured to external routing protocols like BGP (Border gateway protocol) and OSPF (Open Shortest Path First) to another BGP or OSFP of other ISP or large organization.
Subscriber Edge Router: These router are deployed in an end user (enterprise) organization. These are used to connect organizations to other branches or with ISP.
Inter-provider Border Router: These routers are used for Interconnecting ISPs. These routers support multi-routing protocols for secure data processing and high performance.
Core Router: Core router is used as the backbone of the LAN network. In some deployment scenarios, a core router may perform as a step-down backbone that interconnects the distribution routers from different branches of an organization. These routers possess high performance capabilities.