To understand the concept of a database think of a file cabinet.  The file cabinet has drawers that contain file folders.  Each file folder contains information.  The file folders are arranged in a particular order, perhaps alphabetically. 

A database contains tables (drawers).  Each table contains records (file folders).  Each record contains information like name, address, phone number, or any other type of data.  One table (drawer) might contain customer records, while another table (drawer) contains a list of products.

In a file cabinet, the information can only be arranged in one way.  In a database you can quickly re-arrange how the records are ordered.  With a mouse click you can change the record order from alphabetical to ID number. A database allows you to create relationships between tables (drawers).  For example, you can connect a customer list to a product list to show which customers buy particular products.

Databases are great for recording information about things that happen over and over in only slight variations.  Like a spreadsheet, a database may contain formulas.  In a database the formulas do not have to be re-written or copied each time a new record (row) is added.

Lookup tables store information that is used over and over.  For example, a lookup table could contain a Product ID, Product Name, and Product Description.  Each product's information is stored in one lookup table record.  Each time a sale is made and recorded in a sales table, the product name shows up on the on screen form, but only the Product ID is actually stored in the sales table.  This arrangement saves storage space in the computers and insures that the Product Name is always spelled correctly and described in the same way.

On screen forms or web pates are used to display data from database records on the computer screen.  A form or web page may be used to look at data to to add, edit, and delete data.  Reports are used to output data in different formats.  Reports can be viewed on the computer screen, printed on paper, or sent as e-mail attachments.

Databases are often designed with a front end and a back end.  The back end contain the data and is usually placed on a network file server.  The front end contains the forms or pages and reports as well as other code to work with the data.  If the application is a desktop application, the front end can be installed on multiple computers on the network allowing more than one user to use the data. If the application is a web application, it can also be run from multiple computers even though the front end and back end are located on one or more servers.