An IP (Internet Protocol) address is a unique numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. IP addresses play a fundamental role in networking, allowing devices to identify and communicate with each other on the internet and within local networks.

IP addresses are the backbone of the internet and are used to route data packets between devices. They are an essential component of network communication and play a crucial role in how information is transmitted over the internet.

IPv4 is the older and most widely used IP address type. IPv4 addresses consist of a 32 bit binary number, typically expressed in a human-readable format like "192.168.1.1". The parts of this addresses e.g. "192" is called an octett; Every octett consists of 8 bit. That means that this number can reach from 0 to 255.

Private / Local IP Address: Private IP addresses are used within local networks, like your home or office. They are not globally unique and are used for internal network communication. In a typical setup, a network of local IP-Addresses share one public IP-Address. This works because of NAT (Network Address Translation). For local IPv4 addresses, the specially reserved address ranges according to the IETF (Internet Engineering Task Force) RFC (Request for Comments) documents are usually used. These address ranges are intended for private use and are not intended to be routed on the public Internet. The most common ranges for local IPv4 addresses are:

From 10.0.0.0 to 10.255.255.255

From 172.16.0.0 to 172.31.255.255

From 192.168.0.0 to 192.168.255.255

IPv4 addresses were historically divided into five classes (A, B, C, D, and E) based on their first few bits, but classless addressing is commonly used nowadays for more flexible address allocation.

Class A: 1.0.0.0 to 126.255.255.255

Class B: 128.0.0.0 to 191.255.255.255

Class C: 192.0.0.0 to 223.255.255.255

Class D: 224.0.0.0 to 239.255.255.255

Class E: 240.0.0.0 to 255.255.255.255