Hi Tapas,
These are core components shipped with AEM. There are versioning like V1, V2 to avoid unwanted changes after components upgrade.
Core Components were introduced to provide robust and extensible base components, built on the latest technology and best practices, and adhering to accessibility guidelines. Core components make page authoring more flexible and customizable, and extending them to offer custom functionality is simple for the developer.
The Core Components will be made available with defined AEM versions with which they are compatible. This means that one AEM version may support multiple versions or releases of the Core Components.
More info
Adobe Experience Manager Help | Core Components User Guide
Thanks
Arun
Arun Patidar