What is the difference between ISO and BSI?

Could you elaborate on the key distinctions between ISO and BSI? As I understand, both are involved in standardization, but I'm curious about the specifics of their roles, operations, and the industries they primarily cater to. Does ISO have a broader international reach compared to BSI? Are there any significant differences in their governance structures or decision-making processes? Also, do they collaborate on projects, or are their efforts mostly independent? Clarifying these aspects would help me gain a deeper understanding of the two organizations.