A webform on a web page allows a user to enter data that is sent to a server for processing. Webforms resemble paper or database forms because internet users fill out the forms using checkboxes, radio buttons, or text fields. For example, webforms can be used to enter shipping or credit card data to order a product or can be used to retrieve data (e.g., searching on a search engine).

In addition to functioning as input templates for new information, webforms can also be used to query and display existing data in a similar manner to mail merge forms, with the same advantages. The decoupling of message structure and underlying data allow both to vary independently. The use of webforms for this purpose avoids the problems associated with explicitly creating separate web pages for each record in a database.

Ref: Wikipedia - Web form