What is mean of compression ratio in otto cycle?

The compression ratio in an Otto cycle is the ratio of the maximum volume of the combustion chamber (when the piston is at the bottom of its stroke) to the minimum volume (when the piston is at the top of its stroke). It is a critical parameter that influences the thermal efficiency and performance of the engine; higher compression ratiOS typically lead to better efficiency and power output, but can also increase the risk of engine knock. In general, the compression ratio is represented as (CR = \frac{V_{max}}{V_{min}}).