Meaning of Buddha

Buddhahood in Sanskrit is Buddhatva. In Pali is it called Buddhatta or buddhabhāva. It is the state of perfect enlightment attained by a Buddha. The perfect enlightment is sammāsambodhi in Pali. This refers to the universal and innate property of absolute wisdom.

Is there only One Buddha i.e. Gautam Buddha?

The Buddhavamsa is a text which is part of the Pali Canon of Buddhism. It deals with the life of Buddha. It mentions 29 Buddhas in all. The 27 Buddhas, preceded Gautam Buddha and Maitreya, the 29th Buddha is next to come in future. Gautam Buddha was 28th Buddha. The Buddhavamsa related that in the present Kalpa, there are 5 Buddhas.

1. Kakusandha
   
2. Koṇāgamana
   
3. Kassapa
   
4. Gautama
   
5. Maitreya
   

The fifth Maitreya is a future Buddha. The first among these 5 Buddhas of the present Kalpa is Kakusandha.
Kakusandha is mentioned in the Sanskrit Buddhist texts as Krakucchanda. In Tibet he is known as Khorvadjig. He was born in Nepal, near Kapilvastu. He attained enlightment under a sirisa tree. The second Budha of the present Kalpa was Koṇāgamana. Third Buddha was Kassapa. In Sanskrit Buddhist texts, he is known as Kasyapa. He was also born in Nepal and attained enlightment under a Banyan Tree.