Updated on December 10, 2019:
Google Play Services is used to update Google apps and apps from Google Play. It provides core functionality like authentication to your Google services, synchronized contacts, access to all the latest user privacy settings, and higher quality, lower-powered location-based services.
Google Play services also enhance your app experience.
It also speeds up offline searches, provides more immersive maps, and improves gaming experiences. Apps may not work if you uninstall Google Play services.
If downloads from the Play Store don’t complete, try the troubleshooting steps at you can’t download from the Google Play Store.