Which of the following represents one billion characters?

Concept

Digital storage units describe how many bytes a device or file can hold. In the decimal convention, each larger named unit is one thousand times the preceding unit.

If one character occupies one byte, the number of characters and the number of bytes are numerically equal. Thus 109 characters require 109 bytes.

Application

Apply the one-byte-per-character convention to the quantity in the question.

1. One billion characters = 1,000,000,000 characters.

2. At one byte per character, the required storage is 1,000,000,000 bytes = 109 bytes.

3. The decimal unit for 109 bytes is one gigabyte.

Cross-check and contrast

• A terabyte is 1012 bytes, which is one thousand gigabytes.

• A megabyte is 106 bytes, which corresponds to one million one-byte characters.

• A kilobyte is 103 bytes, which corresponds to one thousand one-byte characters.

• A gigabyte is 109 bytes, which corresponds to one billion one-byte characters.

Therefore, under the stated storage convention, the required unit is gigabyte.