Hello Ganesh,
Please read through this on the wiki, if you haven't already - Application Scope - ServiceNow Wiki
Private application scope
With the help of application access settings (see link in the wiki) you can limit what is available to other parts of ServiceNow from your application. As an example, a conference room booking application can have its own tables and business logic in the Conference Room Booking private application scope. While it can allow other applications to read its records such as a list of available conference rooms, it can prevent other applications from overwriting protected data such as reservation schedules.
Global scope
Applications in the global scope are like shared resources that any application developer can modify. Global scope applications do not have a unique namespace identifier included in their application artifact names, but they can have their own application access permissions. Typically, only applications provided by ServiceNow are in the global scope, however all custom applications created before application scope was implemented are also in the global scope.
You can create an application in the global scope using the Start from global option. You must add the property glide.app.creator.global to the system, and set the value to true. This gives the application a global scope and prevents it from benefitting from application scope protections. This option is intended for those who need to support legacy applications from previous versions.
NOTE: Applications in the global scope are also not eligible for upload to the ServiceNow Store. ServiceNow recommends creating all new applications in a private application scope.
