Risk severity levels provide a quantifiable measurement of the threat posed by any given risk. In a 5x5 risk matrix, there are five different severity levels (negligible, marginal, moderate, critical, and catastrophic). A 4x4 risk matrix has four different severity levels (negligible, marginal, critical, catastrophic), while a 3x3 risk matrix has three different severity levels (marginal, moderate, and critical). Classifying risks in this manner makes it easy to see which risks need to be addressed immediately and which ones can be delayed to a later date (if at all).