What is the difference between WPW and svt?

WPW is a type of SVT. Wpw (wolff-parkinson-white syndrome) is a condition where the ECG is abnormal between episodes of tachycardia. The abnormal findings on the ECG are from an extra electrical connection in the heart that is the cause of the svt. There are other types of SVT where the ECG is completely normal between episodes of tachycardia. In those cases the cause of the SVT is not apparent.
Svt wpw. there are several types of svt. One occurs with wpw. wpw is presence of an abnormal electrical pathway between atrium and ventricle, which is a setup for SVT.