What is the role of the Bab in Baha'ism?

As far as I can tell, the current 'era' is the only one that has seen two Baha'i messengers: the Bab and Baha'u'llah. Why is this?
Was the message of the Bab different from that of his successor, or was he just a kind of prelude to the main figure, like John the Baptist in the OT?

PLEASE no kippedD'SC.
Of course I meant NT not OT.

The Bab took on the same role as John the Baptist in Christianity. Supposedly Baha'u'llah (Glory of God) was prophesied in the Old Testament.

The message from the Bab was partly different from the message of Baha'u'llah.

The Bab had a message that was mainly for the inhabitants of Persia and neighboring countries, to prepare them for the adv ant of a second manifestation. His Station is however equal to that of the other prophets, as He started a whole new revelation and His writings are considered as divinely revealed by the Baha'i community.

The Bab enacted some laws, sometimes very harsh, that were later abolished by Baha'u'llah. Those laws were destined to protect an emerging community of believers and lead the way for the next one.

To conclude, here a short text written by Shoghi Effendi explaining the reason for such laws, in the explanations of the Most Holy Book of the Baha'i Dispensation:
"The severe laws and injunctions revealed by the Bab can be properly appreciated and understood only when interpreted in the light of His own statements regarding the nature, purpose and character of His own Dispensation. As these statements clearly reveal, the B?b? Dispensation was essentially in the nature of a religious and indeed social revolution, and its duration had
therefore to be short, but full of tragic events, of sweeping and drastic reforms. Those drastic measures enforced by the Bab and His followers were taken with the view of undermining the very foundations of Shi'ih orthodoxy, and thus paving the way for the coming of Bah?'u'll?h. To assert the independence of the new
Dispensation, and to prepare also the ground for the approaching Revelation of Bah?'u'll?h, the Bab had therefore to reveal very severe laws, even though most of them were never enforced. But the mere fact that He revealed them was in itself a proof of the independent character of His Dispensation and was sufficient to create such widespread agitation, and excite such opposition on
the part of the clergy that led them to cause His eventual martyrdom."

Bab means door in Arabic and Persian.he is the door to hell.Bauhaus is never recognized as a religion by any other known religion.it was purely a political movement that ac hived nothing..

Im a Baha'i,
The Bab is a Manifestation of God , and He said that Baha'u'llah would come. To be a Baha'i, you have to recognize the Bab and Baha'u'llah and also all the previous Manifestations of God.