Geotagging is the act of adding “Geographical information metadata” like location data (longitude, latitude, etc.) to a media, in our case to pictures taken with our phones. This is what Instagram geo-tagging is about.
Instagram is testing a feature that will let users collect their location data on Instagram and share them with Facebook. The platform is working on a prototype Location History feature proposing that Location History data collected from Location Services within the Instagram app will be used to support Facebook’s ad targeting.