Google Map-Marker icon

  Google Map embedded in Google Search that has a bunch of markers/icons but one of them is the letter P.I asked a bunch of local SEO experts what the letter P symbolizes and so far,Google has used different types of icons in their maps but it seems no one knows what the P is for. They've used H for hospitals, they've tried promotion/sponsored icons, they've used images and different colors.A marker identifies a location on a map. By default, a marker uses a standard image. Markers can display custom images, in which case they are usually referred to as "icons." Markers and icons are objects of type Marker. You can set a custom icon within the marker's constructor, or by calling setIcon() on the marker. See more about customizing the marker image below

Broadly speaking, markers are a type of overlay. For information on other types of overlay.
Markers are designed to be interactive. For example, by default they receive 'click' events, so you can add an event listener to bring up an infowindow displaying custom information. You can allow users to move a marker on the map by setting the marker's draggable property to true. For more information about draggable markers.