Describe the concept of the world beta of a security

Question

Describe the concept of the world beta of a security.
The world beta measures the sensitivity of returns to security to returns to the world market portfolio. This is a measure of the systematic risk of the security in global setting. Statistically, the world beta can be described as:

                                      Cov(R_i, R_M)/Var(R_M),

Here R_i and R_M are returns to the I-th security and the world market portfolio, respectively.