On the internet, every device is assigned a unique IP address by the internet service providers for a certain time period. Since the one ISP uses only a certain range of IP addresses in a particular geographical region, you can estimate the location of the device based on the IP address assigned to it. For example, if the AT&T assigns you an IP address 166.137.12.34 then you can find out that it lies within a range of IP addresses assigned by AT&T in Doylestown, Pennsylvania. But you do not have to it all manually. You can use tons of services available online, for example, BearsMyIP.
The BearsMyIP is a IP addresses finding web app designed by the same people who have created TunnelBear VPN. It is very useful if you want to know your IP address and the geo-location information after changing or hiding your IP address through the use of a VPN service (like TunnelBear) or after rebooting your modem.
To use the BearsMyIP service you have to simply visit their website and in a few seconds you will be shown you IP address along with host name and the internet service provider information. Not to mention that you geographical location is pin-pointed on the map of the world.
If you want to copy this information into the clipboard, then you can click/touch on the small Copy to clipboard button. The information copied is the IP address that you are currently assigned, the host name and the name of your ISP or VPN service provider.
You can visit the BearsMyIP website at https://bearsmyip.com/.