Because the size of addresses is limited, the maximum amount of memory is also limited. 32-bit processors can usually only handle up to 4 GB of RAM. This is the number of different bytes that can be selected using a 32-bit address (each bit can have two values—0 and 1—and 2 bytes is 4 GB). A 64-bit processor might be able to handle up to 16 EB of RAM (16 exabytes, around 16 billion GB, or 16 billion billion bytes). The operating system may limit it to using smaller amounts.