Computers store information in the form of "1" and "0"s in different types of storages such as memory, hard disks, usb
drives, etc, to be processed by software. The most common digital data storage unit is byte which is 8 bits.
For your information, computer data is expressed as bytes, kilobytes, megabytes as it is in metric system, but 1 kilobyte is 1024 bytes not 1000 bytes. This often causes confusion.
Data storage units starting from the smallest are: bit, byte, kilobyte (kb), megabyte (mb), gigabyte (gb), terabyte (tb), petabyte and exabyte.