Fields, Records and Files

Fields

A field is the smallest unit of data in a record and it contains an individual piece of data.
Types of data that can be held in a field might include strings (text), integers (whole numbers), floating point numbers (numbers with decimal points), or Boolean values (true or false).
Each field in a record has a unique field name which is used to identify it.
The type of data which can be held in a field is determined by the data type of that field.
Fields, like array elements, can be accessed directly using their index number.

A record is a collection of related fields that can be treated as a single unit.
In database terminology, a record corresponds to a row in a table.
Each record is made up of several fields and each field in a record holds a unique piece of data.
Primary key is a special field in a record that makes each record unique and ensures that no two records are identical.

A file is a collection of related records.
In the context of databases, a file corresponds to a table where each row is a record and each column is a field.
The structure of a file is defined in its file specification or schema, which includes the names of fields, their order, and their data types.
Files can be sequential files, where records must be accessed in the same order they were added, or random access files, where records can be accessed in any order.
Files can also be indexed, meaning they have an index that allows quick access to any record, similar to the index of a book.
Text files store data in human-readable form, while binary files store data in a format that can only be read by a computer.
Files are stored on a permanent storage medium, such as a hard disk, which allows data to be retained even when the computer is turned off.