1. Bit:
The smallest unit of data storage, each binary digit 0 or 1 represents a bit
2. Byte (byte):
Eight bits form a byte
1byte = 8bit
1KB = 1024byte
1MB = 1024KB = 1024 *1024byte
1GB = 1024MB
3. Characters:
one man or one English means one character, one English letter occupies one byte, and one man occupies about two bytes