Your customer experience strategy is the unifying mission that your team operates under to give the best possible customer experience it can. Without it, your team may not know what your CX standards are, how they can define success, or how to make decisions.
Your customer experience strategy relates to how your customers are treated and what your standards are for how the service experience should go (not to be confused with your Customer Service Strategy, which relates more to the practicalities of how you will offer support, what channels you use and how quickly you respond).
For example, your customer experience strategy might include a written set of core values for all service interactions. Or a company might track its Net Promoter Score and other customer feedback to continuously improve the service experience.