App store optimization (ASO) is the process of increasing an app or game’s visibility in an app store, with the objective of increasing organic app downloads. Apps are more visible when they rank highly on a wide variety of search terms (keyword optimization), maintain a high position in the top charts, or get featured on the store. Additionally, app store optimization encompasses activities that aim to increase the conversion of app impressions into downloads (conversion rate optimization). .
https://en.wikipedia.org/wiki/App_store_optimization