A Web Component is a web object that can be executed independently (like any other web object), or it can be part of another web object. This gives you a high degree of reusability.
The most common examples of use are menus, logins, customization areas, and so on. For example, instead of defining the menu load in every web object that uses it, the idea is to develop it in a Web Component and reuse it in every object that requires a menu.
You have two ways to create a Web Component:
1) By selecting in the main GeneXus menu File > New Object, the New Object Dialog is opened. There, you have to select the Web category, and you are offered to create a Web Component.
2) By selecting the in the main GeneXus menu File > New Object, and after that, by creating a Web Panel or a Transaction and setting their Type property with the Component value.
After having the Web Component defined, in order to use it inside another web object form, you have to insert a Web Component control over the desired web object form and set the corresponding Web Component Control Properties.
Type property (in Web Panels and Transactions)