Memory.

You have it right, a bit is either 0 or 1. They can also be called off and on, as well as clear and set. 8 bits together make a Byte, the basic unit of memeory. Memory is stored in binary, so you can store up to 11111111 in one byte, which is equivalent to decimal 255. When looking at computers, though, you usually look at the specs in much bigger units, such as kilobytes, megabytes, and gigabytes. A kilobyte (also known as just K for kilo) is 1024 bytes. A megabyte is 1024 kilobytes or 1048576 bytes, and a gigabyte is 1024 megabytes or 1048576 kilobytes or 1073741824 bytes. Also, each BYTE has an address, not each bit. Byte 1 has an address of 1 and byte 10000 has an address of 10000.

Since every computer is slightly different, there are probably websites and probably a manual for your specific computer, if you want to learn more about the low-level workings. Hope it helps!