The Puranas are believed to have been composed between 400 BCE and 1500 CE, and they are considered to be an important part of Hindu scripture. 

Each Purana contains five main sections: creation, genealogy, mythology, cosmology, and geography. They provide a comprehensive account of Hindu cosmology, including the creation of the universe, the genealogy of the gods and goddesses, the lives and deeds of the great sages and kings, and the significance of various Hindu festivals and rituals.

The Puranas of Sanatan Dharma provide detailed descriptions of the elements of creation, which are believed to be the building blocks of the universe. These elements are traditionally known as the Pancha Mahabhutas, which include:

Earth (Prithvi): Earth represents the solid form of matter and is associated with stability and nourishment.

Water (Jala): Water represents the liquid form of matter and is associated with purity, fluidity, and abundance. 

Fire (Agni): Fire represents the energy form of matter and is associated with transformation, purification, and illumination. 

Air (Vayu): Air represents the gaseous form of matter and is associated with movement, communication, and freedom.

Ether (Akasha): Ether represents the space or vacuum form of matter and is associated with the infinite, boundlessness, and emptiness. 

These elements are considered to be interrelated and interdependent, and their balance is believed to be essential for the proper functioning of the universe. The Puranas of Sanatan Dharma describe how these elements were created and how they interact with each other to sustain the universe. They also provide guidelines for how to live in harmony with these elements to achieve spiritual growth and liberation.

Genealogy is an important aspect of the Puranas in Sanatan Dharma, as they provide a detailed account of the lineage of various gods, goddesses, and legendary figures. The Puranas trace the ancestry of these figures back through a series of generations, providing a comprehensive family tree that includes both divine and human beings.

The genealogy in the Puranas often serves to establish the divine status of various figures, as well as to emphasize the interconnectedness of different gods and goddesses. For example, the Puranas trace the lineage of Lord Shiva and his wife Parvati, as well as their offspring, including Ganesha and Kartikeya.

The genealogies in the Puranas also serve to provide a historical context for various legends and myths. For example, the Puranas provide a detailed account of the lineage of Lord Rama, the protagonist of the Ramayana, and his ancestors. They also trace the ancestry of Lord Krishna, the protagonist of the Mahabharata, and his descendants.

The Puranas in Sanatan Dharma are a rich source of mythology, containing numerous stories and legends about the gods, goddesses, and other divine beings. These myths often convey deep philosophical and spiritual teachings through the use of allegory, symbolism, and metaphor.

Many of the myths in the Puranas focus on the deeds and exploits of various gods and goddesses, such as Lord Shiva, Lord Vishnu, and Goddess Durga. These myths often explore the divine qualities and attributes of these figures, such as their power, wisdom, and compassion. They also provide insight into the role of these deities in the creation and maintenance of the universe, as well as their interactions with humans and other beings.

Cosmology is an important aspect of the Puranas in Sanatan Dharma, as they provide a detailed description of the universe and its origins. The Puranas describe the universe as being composed of multiple worlds or lokas, each with its own unique characteristics and inhabitants.

According to the Puranas, the universe is believed to be cyclical, with periods of creation, maintenance, and dissolution. The creation of the universe is said to be the result of the interplay between the three gunas or qualities of nature, namely, sattva (purity, balance), rajas (activity, passion), and tamas (inertia, darkness). The Puranas describe how the universe was created from the cosmic egg or Hiranyagarbha, which emerged from the waters of chaos and was then divided into various planes of existence.

The Puranas also describe the different lokas or worlds that make up the universe, including the earthly realm or Bhuloka, the realm of the gods or Swargaloka, and the realm of the ancestors or Pitraloka. These worlds are believed to be interconnected and interdependent, with beings moving between them depending on their karma or actions.

The cosmology in the Puranas also provides insight into the nature of time and the cycles of creation and dissolution. The Puranas describe the four yugas or epochs that make up a cosmic cycle, each with its own unique characteristics and qualities. The Puranas also describe the end of the cosmic cycle, known as pralaya or dissolution, in which the universe is absorbed back into the cosmic egg until the next cycle of creation begins.

Geography is an important aspect of the Puranas in Sanatan Dharma, as they provide a detailed description of the physical world, including the continents, oceans, mountains, and rivers. The Puranas also describe various regions and kingdoms that existed in ancient India, as well as the myths and legends associated with them.

The Puranas describe the physical world as being composed of seven continents, each surrounded by seven oceans. The seven continents are said to be Jambudvipa, Plakshadvipa, Shalmalidvipa, Kushadvipa, Krouncadvipa, Shakadvipa, and Pushkaradvipa. Jambudvipa, the central continent, is believed to be the home of humans and is considered the most important.