Varchar is used to store variable length alphanumeric (non-Unicode character) data which supports space efficiency and store data without wasting the extra space. Due to non-Unicode conduct, it takes 1 Byte per character. The storage size is the actual length of the data entered + 2 bytes. A varchar column defines the string length and can be a value from 1 through 8,000. Varchar indicates that the maximum storage size is 2^31-1 bytes (2 GB).
A varchar must mean you can store any string of any length in it and you can set it as VARCHAR (MAX).