What's the difference between clicking on apply or ok?

[textbook]

For example when I go to 'msconfig' and try to stop certain things coming on when computer starts up it gives the options of clicking on apply and ok, what's the difference between these two?

On another note, if you change flats (change where you live) but use the same laptop, does your IP change?

 

[johnb35]

if you change flats (change where you live) but use the same laptop, does your IP change?

If you are connected to a different internet service, yes your IP will change.

it gives the options of clicking on apply and ok, what's the difference between these two?

Clicking apply sets it correctly and ok will close the window.