An IPv4 address is a unique identifier assigned to each device connected to a computer network that uses the Internet Protocol for communication. It consists of four sets of numbers, each ranging from 0 to 255, separated by periods. For example, an IPv4 address might look like 192.168.1.1. This format allows for approximately 4.3 billion unique addresses. IPv4 addresses are essential for routing data across the internet, ensuring that information sent from one device reaches the correct destination. However, due to the growing number of devices, the availability of IPv4 addresses is limited, leading to the development of IPv6, which offers a much larger address space.