Thirty facts are common to all the Buddhas. For example, he is mindful of his conception in his last birth as a Bodhisatta and he is seated cross-legged in the womb of his mother. His mother delivers him in standing position in a forest. When he was born, he immediately takes seven steps; and roars like a lion. There are thirty-two specially visible marks on the body of the Buddha, which are, for example, the signs of the wheels with spokes on his soles; projected heels; long digits; soft hands and feet; straight fingers and toes; shell-like round ankles; antelope-like legs and the length of the hands to touch the knee without bending; smooth golden hued stainless skin; black eyes; lion-like chaste; long tongue; forty-teeth and so on.
There are eight particular characteristics, which differentiate one Buddha from the other. These are the height of his body; his social rank; the area of his aura; the passage used to renounce the worldly life; the tree under which he attains Enlightenment; the size of his seat under the Bodhi tree (palanka); the length of his austerities; and his longevity.
Furthermore, one Buddha appears only once and more than one Buddha may be born in one aeon (kappa). The aeon having only one Buddha born is called Sarakakappa, when its two Buddhas are born in an aeon the Kappa is called Mandakappa , if its three in an aeon the Kappa is called Varakappa. When four are born in an aeon is called Saramandakappa; and if five Buddhas are born in an aeon, which is an extremely rare phenomenon, the Kappa is called Bhaddakappa.
But further, no Buddha is born until the order or the teaching of the previous Buddha completely vanishes from the earth. According to the tradition teachings of Gotama Buddha shall vanish after five thousand years.