'Auto-wait Time out' & 'Set auto-wait Time out for operations'

Hellow! 

I wonder  ' Auto-wait Time out' & 'Set auto-wait Time out for operations ' .

When I set up the 'Set auto-wait Time out for operations ' using right mouse button and run. 

And
After exit the test,  'Set auto-wait Time out for operations ' return to default value. 

How can I fixed value( 'Set auto-wait Time out for operations ' ) that I want?

What's the different 'Auto-wait Time out' & 'Set auto-wait Time out for operations ' ?