Prime (rank)

When a new matrix-bearer is chosen, if the a Transformer has affinity for the matrix, he may be transformed into a super-powerful Prime.

Primes are appointed for life, serving until either their deactivation of choosing to step down.

Not all matrix-bearers are Primes. Conversely, most Primes are Autobot leaders, because the Matrix of Leadership is besowed on well, leaders. The relationship is largely corrrelary however, nto causal. (They were chosen to bear the Matrix because theyw ere great leaders, they were not made leaders because they're some schmutz with the Matrix.)

Japanese equivilant: Convoy

[Note: Not all Convoys are Primes. If you can lead ants to a picnic, you're a Convoy in Japan.]

From Teletraan I: The Transformers Wiki, a Wikia wiki.