What are the for stages of how the universe formed?

The universe formed through four key stages:

1. The Big Bang: Approximately 13.8 billion years ago, the universe began as an extremely hot and dense point, which rapidly expanded.
2. Nucleosynthesis: Within minutes, temperatures dropped enough for protons and neutrons to combine and form the first atomic nuclei, primarily hydrogen and helium.
3. Recombination: About 380,000 years later, electrons combined with these nuclei to form neutral atoms, allowing photons to travel freely, leading to the Cosmic Microwave Background radiation.
4. Structure Formation: Over billions of years, matter began to clump together under gravity, forming stars, galaxies, and larger cosmic structures, shaping the universe as we observe it today.