What's the purpose of "Power Rankings"?

NBA(and other sports too) related sites usually have this column called "power rankings" which I still do not know what it's for. It ranks current nba teams according to their recent performances. At first I thought it was some annual prediction those analysts like to do b4 season starts but after a while I found out that power ranking changes as seaons goes by so it should be more than prediction. What I don't understand is that there's is already something called "Standings" which tells you who's doing good and who's not so what on earth is this power rankings for?

Standings show how the team has played to date...but Power Rankings are usually weekly and thus show how the team performed in the last week...plus it allows for the creator of the Power Ranking to opine on the teams...

power rankings is basically llike how each team performed each week which is a bit different from the standings...for example if the magics went 4-0 for the week vs. the pacers, kings, lakers and dallas, there power rankings would be much better than there standings

for example if the magics went 4-0 for the week vs. the pacers, kings, lakers and dallas, there power rankings would be much better than there standings

If this example were true, the Magic would still be 29th in the real standings but most likely will be ranked in the top 3 on the power rankings.