The diagram below shows plate divergence which allows magma to come up from the mantle. This is occurring in the Great African Rift Valley (X).
W is pointing to the San Andreas Fault which involves the North American plate and Pacific plate slipping and sliding past one another.
Y is pointing to the Himalayas formed from the convergence of the Indian and Eurasian continental plates.
Z involves the subduction of the Pacific plate underneath the Eurasian plate.