In sutra, ground is the illusory world we see in front of us, which includes sentient beings, the external world of mountains, rivers, earth, etc., and emptiness; fruition is the attainment of the three resultant bodies of buddhahood—the dharmakaya, sambhogakaya, and nirmanakaya. We ordinary people are not yet buddha, but through practice we can attain buddhahood after three asamkhyeya kalpas. Sentient being is the cause; buddhahood is the result.

~Depicted from GATEWAY TO VAJRAYANA PATH - Vajrayana Terminology