1, with different definitions: the critical point refers to the point where the system changes qualitatively or transiently when a certain parameter reaches a certain value, while the zero boundary point refers to the turning point where the system state changes when a certain physical or chemical quantity reaches a certain value.

2. Different characteristics: the critical point is a stable point, and the state changes around it can be described by certain laws, while the zero boundary point is an unstable point with various state changes around it.

3. Different application fields: the critical point is mainly used in physics, chemistry, biology and other fields to describe the turning point in the process of material state change and chemical reaction, while the zero boundary point is mainly used in physics, mathematics and other fields to describe the turning point of physical quantity or mathematical function at a certain value.