Final answer:
IPv4 supports approximately 2³² or 4,294,967,296 unique addresses as it uses 32-bit addressing.
Step-by-step explanation:
IPv4 supports approximately 2³² addresses. This is because IPv4 addresses are 32-bit numbers, meaning they consist of four octets (or bytes), with each octet represented by 8 bits. Because each bit can be either a 0 or a 1, there are 2 possible values per bit, so with 32 bits, there are 2³², or 4,294,967,296 possible unique addresses.