I'm familiar with CTS(Compatibility Test Suite). But recently I came across the term GTS, which as per my understanding is also a Google's compatibility test suite. But I don't have enough information regarding this. I googled for the difference between CTS and GTS but strangely and sadly didn't get anything specific. If anyone here knows about this, please tell me something.
GTS is a list of requirements that the tablet must comply with in order for that tablet to be “Google Certified” and have permission to preload the Google Market Suite(“GMS”)
Just read this links for in details.