What is the meaning of "one, two, one" in cha-cha-cha dance?

This is a command issued for dancers to master the rhythm, just like "one, two, one" in marching.

Each Latin dance has its own rhythmic pattern, but it is not like marching in unison, but there are fast and slow, fast and slow changes have their own rules and programs. When the length of the slow beat is equal to the length of the two fast beats, the rhythm of "slow, slow, fast, fast" is read in accordance with the rhythm of equal length, which becomes "one, hitch, two, hitch, three, four."......