What is the difference between wire and reg?
Net types: (wire,tri)Physical connection between structural elements. Value assigned by a continuous assignment or a gate output. Register type: (reg, integer, time, real, real time) signifies abstract data storage element. Assigned values only within an always statement or an initial statement. Main difference between wire and reg is wire cannot hold (store) the value when there no connection between a and b like a->b, if there is no connection in a and b, wire loose value. However reg can hold the value even if there in no connection. Default values: wire is Z,reg is x.