Check the below links and serch for Visual composer in the below docs .then you can see the differences.
Here is some information regarding WAD Vs Visual Composer.
Visual Composer Capabilities Compared to BEx WAD:
Whereas the BEx Web Application Designer is tailored to business analysts who are focused on a pure BI and BI Planning context, the Visual Composer is a tool that allows business analysts to integrate data of any kind (BI data and transactional data).
Both tools allow users to design applications in a code-free and WYSIWYG environment.
Visual Composer is web-based; BEx Web Application Designer is a MS Windows application. In the future, you will be able to compile VC models in HTML-B and Macromedia Flash, as well as other formats. BEx WAD renders Web applications in HTML.
The Visual Composer BI Kit that is shipped with the Visual Composer provides functionality that helps integrate BI data into your Visual Composer models. You can run these models as iViews in the SAP Enterprise Portal.
Web Application Designer Focus
The BEx Web Application Designer allows business analysts to build BI Web applications and dashboards that fully leverage SAP BIu2019s analysis and planning services.
With the BEx Web Application Designer, you can access SAP BI and third-party BI data and build highly interactive planning and analysis applications.
Visual Composer BI Kit Focus
The VC BI Kit can access SAP and non-SAP data (including OLAP and relational data) using the BI Java Connectors. It allows business users to build applications that are highly integrated with transactional data from an ERP system, for example. SAP BI is just one of a number of possible data providers.
Multidimensional analysis and planning is not the current focus of Visual Composer as these services are only provided in the BEx Web Application Designer.
The following graphic provides an example of a SAP xApps Analytics model (blocked order list in the financials area):
The composite application provides a credit manager with an overview on the list of sales orders that have been blocked due to failed credit checks and the ability to clear that list.
Some More information regarding Visual Composer Compatabilitis::
If you want to develop scenarios that require data from different systems and are more process oriented, use a Visual Composer model instead of using the Web Application Designer to design Web templates. Use the Visual Composer especially if you want to develop composite applications.
VC models are deployed in the portal and can be accessed from the portal content objects (iViews, pages, and so on).
Visual Composer Capabilities
u2022 One integrated and common design environment that allows the creation of any type of application and goes beyond the scope of BI
u2022 Integration with SAP NetWeaver BI data as well as with heterogeneous data sources and transactional data
u2022 VC allows you to build composite applications with a fully web-based tool that displays analytical data, performs business analytics and also integrates this with SAP ERP data
u2022 BI extension kit within Visual Composer allows business analysts to create analytical content for SAP Enterprise Portal in an easy and intuitive manner
u2022 VC allows you to fully integrate and leverage the BI-specific tools of the Business Explorer (BEx) Suite
u2022 VC allows you to use the BI Java Connectors to create analytical content based on any type of data service in an SAP Enterprise Portal system and visualize the result in an iView
Visual Composer BI Capabilities
u2022 Offers integration with BI InfoProviders (for example, Info Cubes, BEx queries and query views, BEx Web applications) using WEB API as well as with heterogeneous data sources (including OLAP and relational data sources) using Java Connectors
u2022 BI Query Wizard - freeform modeling for XMLA connector: The BI query wizard offers a freeform modeling template for XMLA connectors. This allows you to take an existing scheme and select the members that you want to display. It allows you to sort in the query and set filters in the query.
u2022 Exceptions: The Web API for SAP BI returns exception information in the result set if you have defined exceptions for the query or query view. Coloring is used to display these exceptions in grid control. The same coloring is used as in BI by default.
u2022 Exceptions editor: The exceptions editor allows you to define exceptions for BI data sources on the Visual Composer side
u2022 Alert dataservice and alert monitor: Based on the alert framework, the new alert data service offers all alerts. These can only be filtered to BI alerts and are displayed in a grid control as an alert list.
u2022 Integration of MDX and SQL editors in the formula wizard: With the integration of the MDX and SQL editors, you can enhance MDX and SQL statements with formulas so that the parameters that are calculated at runtime can be used flexibly.
u2022 Favourites and history for BEx queries and query views: The history stores accesses to BI queries and query views from the Visual Composer story board. In addition, you can maintain BI favorites from the Visual Composer.
u2022 Info Object Data Service: This new data service allows you to access and use master data from BI InfoObjects. This allows you to fill dropdown boxes and other controls with master data.
u2022 Text elements: In the output port, BI data services provide additional information about the last update of the data in the underlying InfoCube, the person who last changed the data, and so on. This information can be used in the application to inform the user about the accuracy of the data.