What does the side bar showing all your friends on facebook mean?

[*BaB*]

You know that bar on the side where it says the amount of friends you have and then it shows them, well my sister said that bar shows people who've recently been on your profile, is that true? Or what is it? Also, is there a possible way to see who's been on your page, thank you
not the chat bar

[GACfan12345]

A little green circle comes up when they are online. And you can click on there pic and chat with them.

[Jo Han]

It's the chat bar. There is an app that lets you see who visits your profile, but it will only work if the other person is using the same app too. You can't tell if someone who does not have the app visits your profile.

[Polly]

There is no certain way to find out who has been looking at your profile.The side bar does indicate who has been on your profile recently apparently but it also can be who you have had recent communcations with also. e.g.Looking at your friends comments on a status or they may have looked a pic of yours on their newsfeed.

[Tadami]

On which side of the website? The same side as the chat bar? Does it stay on the screen as you move from place to place like the chat bar does? ._. Be more specific..