Plates are undergoing convergence at some point and divergence at other point you can understand through the example that the Eurasian plate and Indian plate undergone convergence and led to the formation of Himalayan mountains and the Tethys sea got vanished over a period of time but still the African and the Eurasian plates are undergoing convergence and the Mediterranean sea which is a remanent of Tethys sea over some million of years will be vanished and we'll find the same case that happened in Himalayan mountains.
We can consider one more example that is the Arabian plate that got separated from the African plate and now through the eastern rift valley region of Africa we can make out that the Somalian plate will get separate through the rest of the African plate over a period of time.
