Hinduism
A Hindu temple is a house of god(s). It is a space and structure designed to bring human beings and gods together, infused with symbolism to express the ideas and beliefs of Hinduism. A temple incorporates all elements of Hindu cosmology, the highest spire or dome representing Mount Meru – reminder of the abode of Brahma and the center of spiritual universe, the carvings and iconography symbolically presenting dharma, kama, artha, moksha and karma. The layout, the motifs, the plan and the building process recite ancient rituals, geometric symbolisms, and reflect beliefs and values innate within various schools of Hinduism. Hindu temples are spiritual destinations for many Hindus (not all), as well as landmarks for arts, annual festivals, rite of passage rituals, and community celebrations.
Hindu temples come in many styles, diverse locations, deploy different construction methods and are adapted to different deities and regional beliefs. Two major styles of Hindu temples include the Gopuram style found in south India, and Nagara style found in north India. Other styles include cave, forest and mountain temples. Yet, despite their differences, almost all Hindu temples share certain common architectural principles, core ideas, symbolism and themes.
Hinduism
Hinduism is an Indian religion and "dharma", or way of life, widely practised in the Indian subcontinent and parts of Southeast Asia. Hinduism has been called the oldest religion in the world, and some practitioners and scholars refer to it as "Sanātana Dharma", "the eternal tradition", or the "eternal way", beyond human history. Scholars regard Hinduism as a fusion or synthesis of various Indian cultures and traditions, with diverse roots and no founder. This "Hindu synthesis" started to develop between 500 BCE and 300 CE, after the end of the Vedic period (1500 BCE to 500 BCE), and flourished in the medieval period, with the decline of Buddhism in India. 
Although Hinduism contains a broad range of philosophies, it is linked by shared concepts, recognisable rituals, cosmology, shared textual resources, and pilgrimage to sacred sites. Hindu texts are classified into Śruti ("heard") and Smṛti ("remembered"). These texts discuss theology, philosophy, mythology, Vedic yajna, Yoga, agamic rituals, and temple building, among other topics. Major scriptures include the Vedas and Upanishads, the "Bhagavad Gita", and the Āgamas. Sources of authority and eternal truths in its texts play an important role, but there is also a strong Hindu tradition of questioning authority in order to deepen the understanding of these truths and to further develop the tradition.