In IPv4, how many bits are there in an address?

In IPv4, addresses are composed of 32 bits. This means that an IPv4 address consists of four octets, with each octet containing 8 bits. The total of these bits allows for a vast number of unique addresses—specifically, 4,294,967,296 possible combinations.

This structure is fundamental to the way devices communicate over a network, enabling the identification of each device with a unique address. The 32-bit architecture is a key characteristic of IPv4, distinguishing it from other address types in the networking world. For example, IPv6 uses a 128-bit address format, which allows for a significantly larger address space to accommodate the growing number of devices connected to the internet.

The other choices—16 bits, 64 bits, and 128 bits—do not apply to IPv4 addresses. They represent either outdated or significantly more advanced systems, but they do not reflect the standard established by IPv4.