Is there any Standard Object in salesforce which is also a Junction Object?

Hi Suraj

Yes suraj Pricebook entry is an object in the salesforce which is standard object and junction object to :

For getting information about  Pricebook entry go  to the schema builder by typing it in quick search box in the setup:

where you filter the objects by typing pricebookentry in search box and you will get information about junction object pricebook entry

Hope this may help you:

thanks