Origin story
Venkateswara is the form of Vishnu enshrined on the Tirumala hills in Andhra Pradesh, revered across South India as the lord of the seven hills. The temple tradition tells of Srinivasa, who took a loan from Kubera for his wedding to Padmavathi and is said to accept the offerings of devotees until the debt is cleared.
The deity's namam mark on the forehead is said to carry the footprint of the lord, and the serpent crown marks his cosmic power. For countless devotees the pilgrimage to Tirumala is an act of humility: wealth is given up at the foot of the hill, and vows are fulfilled at the sanctum.
Source: Wikipedia: Venkateswara Temple, Tirumala — https://en.wikipedia.org/wiki/Venkateswara_Temple,_Tirumala