What is an IPv4 Address ?

An IPv4 address is a 32-bit numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. It serves two main functions: identifying the host or network interface, and providing the location of the host in the network.

An IPv4 address is typically represented in the form of four decimal numbers separated by periods, also known as "dotted decimal" notation. Each number can range from 0 to 255, and each represents an 8-bit number, referred to as an octet. For example, the IP address "192.168.1.1" is made up of four octets: 192, 168, 1, and 1.

Each IP address can be divided into two parts: the network address and the host address. The network address identifies the network that the host is connected to, while the host address identifies the specific host within that network. The boundary between the network address and the host address is determined by the subnet mask.

There are two types of IP addresses: public and private. Public IP addresses are globally unique and are used to identify devices on the internet, while private IP addresses are used on local networks and are not globally unique.

IPv4 addresses are the most widely used type of IP addresses today. However, due to the limited number of IPv4 addresses available, IPv6 addresses, which have a larger address space, are being adopted to address the shortage of IPv4 addresses.

It's important to mention that IPv4 addresses can be grouped in a CIDR block and CIDR blocks can be used to create a VLSM(Variable Length Subnet Mask) which allows a network administrator to divide an IP address space into subnets of different sizes, depending on the needs of the network. This is more efficient than using a fixed subnet mask because it allows the administrator to use the available IP address space more effectively.