Does Multithreading Always Provide Better Performance Than Single-threaded System?

Does Multithreading Always Provide Better Performance Than Single-threaded System? Does multithreading always provide better performance than single-threaded system? – Multithreads will have least impact. MultiThreading in Multi Core CPU : Multi core can run as many threads as the number of core in CPU. This will surely have performance boost. But Running higher number of