This software provides multiple services to other applications: Location from wireless signals (via Google Location Service), sending and receiving of unified push notification (via Google Push Messenging), silent update of appllications, etc ...
Many software packages depend on it. All the Google apps (YouTube, Google Play, Hangouts, Maps, etc ...) but also many third-party applications that run for (get the position of the user, receive push notifications, etc ...), will be based on a service which is present on almost all Android: GooglePlayServices.
Behind this practical aspect, Google has the necessary cornerstone to control the Android ecosystem. Manufacturers are required to preinstall for the right to sell Android devices! It is necessary to access the main source software: Google Play.
Its source code and are operating remain opaque. The software has a permanent connection to Google's servers. Data exchange made are encrypted and you can not be aware. The installation must be done before starting the system because the software takes control of your system and runs as root (otherwise it could not do last quiet day for example).
Google can therefore, permanently and without delay, delete, modify, install or run what he wants on your smartphone without your consent. (But you might have to doubt when Google told you that you could erase your smartphone remote ..)
In addition, the permanent connection refers to any time position in Google as soon as possible, even when your wifi is turned off.
This should already rebelling. But the most funny is that this constant data flow pump with Google to death on your battery, even in standby. It's beautiful, you buy a smartphone and Google unaffordable expense battery spy on you, haha. By removing GooglePlayServices, you will increase your range of about 1/3. Just that.
I have a Samsung Galaxy S3 has 3 years now and I want 48H in daily use (use about 2/3 hours per day: RSS, email, web, chat, and video) and I do not put out the night. If I use it rarely me in the day between morning and evening, I lost only 25% of battery: p. Uncompromising (I have a sychro contacts / calendar. A Jabber messaging, receiving emails in push notification ....)
Unfortunately GooglePlayServices does not remove a click as you may have read. To my knowledge, you have to reinstall a virgin like Cyanogen ROM and therefore do not install Google Apps.
To replace Google Play as source software, you have F-Droid, which contains only free software (spyware guaranteed, and rarely related to online services Again. CPU consumption and reduced radio)
And if you lack of software available only on Google Play, you can download the APK format from my GooglePlayDownloader software (Linux requires good ... that's another story)