For 189 you nominate an occupation that is in the SOL list, as long as you make 60 points and its not a Pro rata occupation you are very likely to get an invite.You get the invite you apply and you get the Visa and now you can live anywhere in Australia.
For 190 you need state sponsorship and you get extra 5 points for 190 state sponsorship. Now if you are willing to do that meaning the state is willing to sponsor you, you get extra 5 points and using those you might make it to 60 or maybe more points…for pro rata occupations which are in great demand… With the 190 the expectation is that you will work in the nominated state for 2 years after the grant of the visa….
For 489 you need state sponsorship and you get extra 10 points for state nomination and you have to live and work in a designated regional area for a certain time before you are granted a PR. Its easier to get a nomination for a 489 as compared to a 190.
Hope this helps.. Good luck with everything