HPTLC is an advanced form of thin layer chromatography with a thinner stationary phase layer and smaller particle sizes, allowing for faster separations, shorter migration distances, and quantitative analysis through scanning. Key differences between HPTLC and TLC include the thinner stationary phase, wider selection of phases, automated sample application, and use of scanning for quantitative and qualitative analysis. HPTLC provides advantages like simultaneous processing of samples and standards, lower analysis time and cost, simple sample preparation, and non-destructive detection methods.