Using <b> elements for bold text (old way, not good)

Crown shyness is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy.

Using <span> elements with classes for bold text (new way, better)

Crown shyness is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy.

Using multiple CSS selectors together

This text should be bigger

Introducing pseudo-classes and the hover state

Hover over me to change my color