What is the difference between char and varchar data types?
The char is a fixed-length character data type, the varchar is a variable-length character data type. Because char is a fixed-length data type, the storage size of the char value is equal to the maximum size for this column. Because varchar is a variable-length data type, the storage size of the varchar value is the actual length of the data entered, not the maximum size for this column. You can use char when the data entries in a column are expected to be the same size. You can use varchar when the data entries in a column are expected to vary considerably in size.
