参见： asp.net mvc - 有状态和无状态之间的区别是什么？ - 程序员堆栈交换 [ ^ ]。

Http is inherently stateless. So state must be built into your applications

Stateless - There's no memory (state) that's maintained by the program

Stateful - The program has a memory (state)

To illustrate the concept of state I'll define a function which is stateful and one which is stateless

Stateless

//The state is derived by what is passed into the function

function int addOne(int number)
{
    return number + 1;
}
Stateful

//The state is maintained by the function

private int _number = 0; //initially zero 

function int addOne()
{
    _number++;
    return _number;
}