A router is a a very useful device. You need it to get onto internet. It is also complex and simple device. It is simple because you just need to plug broadband cable into it and power it and set it once and you are ready to go. It is complex because inside this tiny box lots of things are going on to provide you wifi signal. Lets look at some of the terminology associated with routers. MAC Address Every device whether it computer, laptop, smartphone, router, modem, printer, camera¬† that is connected to network whether LAN, WAN or internet has MAC address. A MAC address uniquely identifies the network interface of device. Every device has unique mac address in the world. If there are more than one network interface in a device, that device will have two MAC addresses. MAC in MAC address stands for media access control. IP Address IP address is numeric address assigned to devices that are connected to internet. An IP address identifies device on internet and helps devices communicate with each other. One can find information like city, region, country, ISP from IP address. This greatly helps in tracing device. All big internet companies like Google, Facebook, Twitter keep logs of user IP addresses to prevent fraud and cyber crimes. Router Router is special device that joins different computers and routes data between them. Some routers only have Ethernet connections. Other routers have both Ethernet and wifi connections. All routers come configured with default IP addresse like 192.168.l.l, Modern routers and mesh routers also come with firewall and security layer installed. They act as first layer of protection again computer attack. Gateway A gateway interconnects two networks. Router act as gateway at home as it connects your LAN too outside WAN. Wi-Fi WiFi is wireless local area technology that enables devices to connect to hotspot. It works on radio waves. WiFi uses two radio bands, 2.4 GHz and 5.8 GHz. There are two mode of communication, Wi-Fi ad hoc and Wi-Fi direct. In Wi-Fi ad hoc transmission, one gadget directly communicates with other gadget without any intermediary. LAN LAN or Local Area Newark is networking of devices within small space like home, school, apartment, lab, college or office. Devices in LAN connect to each other via switch, hub or router. LAN is mostly private network. Even a connection between router and single computer is called LAN. WAN While LAN is limited to small area, WAN spans very large geographical area. Multiple LAN can join to form WAN. A LAN can have speed of 1000 megabits per second but a WAN can have speed of only 150 megabits per second. So WAN is quite slower in comparison to LAN. DNS (Domain Name Server) DNS is special computer that mas website name to IP address. Every website on internet has IP address. As we not remember website by IP address, we access it by name. But computers do not understand name. So to fetch a website, computer first send query to DNS to get IP of website. After that it contact machine at that IP to get website. VPN VPN means Virtual Private Network. VPN is in simple terms a technology that provides privacy so that you can connect to blocked websites.