The Camino can mean many things. Probably something different to each person who completes it.
The sea shell is the primary symbol of the Camino. Legend has it that sea shells played a role in the story of Saint James. But as one person also explained it, the shell is shaped in a fashion that all nutrients within the shell are going toward where the pearl is formed. The analogy is that we should be sure that all our efforts are focused on producing the best that we can offer.
I believe the Camino represents our life journey toward Heaven. On that journey we encounter many things. It may be hardship, loneliness, friendships, joy, pain, an awareness of God’s creation, His presence in our lives and the lives of others, the goodness in others, and the beauty of the simple things in life. It is what we take from these experiences and how we form and live our lives that hopefully brings us to the end we seek.