What does redcode compression ratio mean?

Compression ratio is a very important concept in the engine. Compression ratio indicates the degree of gas compression, that is, the ratio of the volume before gas compression to the volume after gas compression, that is, the ratio of the total volume of cylinder to the volume of combustion chamber, which is called compression ratio. Generally, the compression ratio of gasoline engines is 6- 10, while that of diesel engines is relatively high, generally 16-22.