The Noble Eightfold Path begins with Right Understanding or Right View. This begins on the intellectual level, in many ways. We hear the Dhamma. It makes sense to us. This is Right Understanding on a basic level. So, with Right Understanding we understand Cause and Effect, and the Four Noble Truths - Dukkha and the true cause of it.
This motivates us to develop Right Thought or Right Intention - thoughts that are directed towards harmlessness, free from ill-will and cruelty. We start to renounce unbeneficial speech, actions, and livelihood. We make the effort to be concerned with our speech, actions and livelihood (which starts the development of Right Speech, Right Action and Right Livelihood).
We practice the Four Great Efforts, the effort to prevent, the effort to let go, the effort to develop, and the effort to maintain. We practice the Four Foundations of Mindfulness in order to develop Right Concentration, i.e. the Concentration that is preceded and supported by the 7 factors of the Noble Eightfold Path before it.
As we practice this Noble Eightfold Path, we develop experiential understanding, and this experiential understanding deepens the basic Right Understanding, which then deepens our Right Thought, Right Speech etc., spiraling up as we progress on the path. It goes up until we develop much more Right Understanding on the experiential level, although we haven't yet reached the Final Understanding.
So we keep on developing and practicing the Noble Eightfold Path, over and over, developing deeper Right Understanding from experience, and deeper Right Intentions.
Our speech becomes more refined. We practice Heedfulness of our actions, speech and thoughts.
We practice Yonisomanasikara to develop more Wisdom.
We visit a Kalyanamitta so we can hear the Dhamma. What we heard before becomes deeper, and so our understanding gets deeper until finally, hopefully, we reach the Final, Transcendental Understanding. And so the spiral goes up, until we've reached Final Enlightenment.