In database system, a field can have a fixed or a variable length. A variable length field is one whose length can be different in each record, depending on what data is stored in the field.
Variable length fields are useful because they save space. Suppose, for example, that you want to define a NAME field. The length of each NAME field will vary according to the data placed in it.
For example, Dexter is 6 character long, but Dexter Ji is 9 characters long
A Fixed length record is one in which every field has a fixed length.
With Fixed-length fields, you would need to define each field to be long enough to hold the longest name. This would be a waste of space for records that had short names
