There are many questions related about this topic. However there is no complete example for this widely used pop-up type:

Basically i need a popup which will appear the top-right of a Feature (Point) when user clicked on that feature. When i am able to do this, unfortunately pop-up overlaps part of the feature. So probably i should set an offset to the feature.

Additionally when map is clicked, the popup should be removed and also when another feature is clicked, the old popup should be removed as well as new popup has been created.

Which event listeners should i use FeatureSelected or FeatureClicked?

Which popup type should i use Anchored or something else?

Could this be a projection issues problem?

I just started to use openlayers and javascript.