Database testing is known as data validation and integrity testing or back-end testing.

UI testing or front-end testing is also called Application testing or GUI testing.

Database testing involves testing of back-end components, which are not visible to users.

This includes database components and DBMS systems such as My SQL, Oracle.

UI testing involves checking functionalities of an application and its components like forms, graphs, menus, reports, etc.

These components are created using front-end development tools like VB.net, C#, Delphi, etc.

Database testing involves checking stored procedures, views, schemas in database, tables, indexes, keys, triggers, data validations and data consistence check.

UI testing involves checking the functionality of application, buttons, forms and fields, calendar and images, navigation from one page to other, and the overall functionality of the application.

To perform DB testing, a tester needs a thorough knowledge of database concept − like procedures and functions, views, indexes, keys and good hands-on SQL.

To perform UI testing, a tester needs a good understanding of business requirements, application functional knowledge, coding, etc.

Data comes from multiple heterogeneous data sources over web applications, Intranet applications and various other applications.

Data is entered manually into applications. It involves functional testing of front-end applications.