Shared URLSession vs Default URLSession

What is the difference between Shared URLSession and URLSession with default configuration?


In my app i was using URLSession.shared to send a request to server. Now i'm trying to change it to URLSession.init(configuration: URLSessionConfiguration.default).


But if i use URLSession.init(configuration: URLSessionConfiguration.default) all my request are taking more time to load.


Compared to URLSession.shared, URLSession.init(configuration: URLSessionConfiguration.default) is taking more time to load the request.(Shared Session is 5 to 10 time faster than URLSession with default Configuration).


What is the Difference between these two methods?


Why URLSession With Default Configuration is taking more to load the request?


Note: I can't use the shared session for my usecase. I need to create multiple URLSession to send a request.