The resistive wire is inside your resistance and it is he who will heat and vaporize the e-liquid of your electronic cigarette. The resistive wire can be designed in different alloys, the Kanthal is part. But the resistive wire is mainly used for rebuildable atomizers, for example Kanthal is widely used by vapers because it has a good distribution of heat and it has a good resistivity. For the resistive wire Nichrome is also used a lot because it is very reactive but less resistive than Kanthal. NI200 (nickel) resistive wire is used for temperature control as well as SS (stainless steel) because they have very low resistivity.