Why are the given compounds in one homologous series?
$$\ce{CH3-OH}$$ $$\ce{CH3-CH2-OH}$$ $$\ce{CH3-CH2-CH2-OH}$$ $$\ce{CH3-CH2-CH2-CH2-OH}$$
I know that homologous series can be represented by a common general formula and have the same chain length. But I could not answer this question. Can anyone help me?