Name the units of measurements to determine the capacity or volume of a disk?

There's more than just one unit, but I'll hit the basic and most common.

Bit = a single 1 or 0

Byte = 8 bits, typically a single letter, number or character

Kilobyte = 1024 bytes

Megabyte = 1024 kilobytes

Gigabyte = 1024 Megabytes

Terrabyte = 1024 Gigabytes (8,796,093,022,208 bits)