Karl Fischer is absolute titration technique by which presnet amount of water in analyte can be measured with high precision and accuracy. Titration can be volumetric or coulometric depending upon nature of analyte to be detery for it's water content. Volumetric titration is simply Iodo-iodimetric tritration in which mole of idodide used to titrate with titrant (mainly methanol) having analyte to react with present water within analyte to release iodine. (1:1) ratio for mole of iodide used: mole of water released. Coulometric titration based with applying mili coulom current to the titrant having analyte to release water. Applied current is measured against the amount of water released up to the end point. Simple technique but it can be explained much more in detail. Thanks