What phenomena are observed in a liquid before it starts to boil?

Let us consider the processes preceding the boiling of a liquid using the example of water.
When water is heated, first of all, its evaporation from the surface becomes noticeable. The steam itself is not visible. In the form of fog, small droplets of water are visible, which condense in the colder air adjacent to the surface. With further heating, small bubbles begin to grow at the bottom. Air dissolved in water is collected in bubbles. Water evaporates inside the bubbles.