Key points to remember

A database is an electronic filing system for organizing and storing data that relates to a broad subject area, such as sales and inventory.

A database is made up of tables. A table is a collection of rows about a specific subject, such as customers.

A row is a collection of pieces of information about one thing, such as a specific customer.

A column is a specific item of information, such as a customer name.

An index is a set of pointers to rows that you use as the basis for searching, sorting, or otherwise processing rows, such as a customer number.

A primary key is a column (or group of columns) whose value uniquely identifies each row in a table. Because the key value is always unique, you can use it to detect and prevent duplicate rows. It cannot contain null data.

An index in a database operates like the index tab on a file folder, making it easier to find information.

A foreign key is a column (or group of columns) in one table whose values are required to match the value of a primary key in another table.