In liquid chromatography liquid mobile phase flows through the column with stationary phase. The main principle of separation remains the same.
Compounds have different affinity to the stationary phase and are separated while flowing through the column. The compounds separated with liquid chromatography are disolved in the mobile phase. They have lower difussion coefficients than gaseous compound separeted with gas chromatography.
Except thin layer chromatography, majority of liquid chromatography is performed in high-pressure arrangement. The liquid is pushed through the column using high pressure pumps. In this case we are speaking about high pressure liquid chromatography (HPLC).
According the polarity of the mobile and/or stationary phase, the liquid chromatography separations can be divided in numerous methods for different kind of samples.