Actually reading the page will give you:

The energy–momentum relation is consistent with the familiar mass–energy relation in both its interpretations:
E = mc2 relates total energy E to the (total) relativistic mass m (alternatively denoted mrel or mtot ),
while E0 = m0c2 relates rest energy E0 to (invariant) rest mass m0.
Unlike either of those equations, the energy–momentum equation (1)
relates the total energy to the rest mass m0.
All three equations hold true simultaneously.