An IP address (IP for Internet Protocol) is a format number for a network hardware, devices that use IP addresses to communicate with each other via IP-based networks such as the Internet.
Most IP addresses look like this: xxx.xxx.xxx.xxx, this is an IPv4 address. Some other IP addresses look like: xxxx:xxxx:xxxx::xxxx, this is an IPv6 address.
Through the IP address you can find out which sender in the city, which service, and also know their home address with the help of ISP.