Use of Temporary Variables in Scripting

Which is the correct usage? And what makes the difference?

Usage.1:

var BCName = this.BusComp().Name();

var bS1 = TheApplication().GetService("Workflow Process Manager');

....

bs1 = null;

Usage.2:

var bComp = this.BusComp();

var sApp = TheApplication();

var BCName = bComp.Name();

var bS1 = sApp.GetService("Workflow Process Manager');

....

bs1 = null;

sApp = null;

bComp = null;

Cheers,

John Wesly J