Currently the most popular structure is the relational structure. In this approach, tables are used to represent the data. Each table is given a name and is called a relation. There can be many relations in one database. Commercial databases such as Microsoft's Access and Borland's Paradox are examples of relational databases.
Fields can contain a number, an alphanumeric string, a date, a picture, or an entire 'blob' of text.
Record - a record is a collection of fields that contain information about an entity in the table. Information in one table can be related to information in another table. This is an important concept because it enables the data to be organized into smaller and more manageable chunks that can be combined when needed. To illustrate this concept consider a database containing some demographic and some clinical information. One could decide to enter all these data into one table, but this involves much duplication of information.