how to call one lightning component from another code example

Example 1: calling lightning component from another lightning component

var evt = $A.get("e.force:navigateToComponent");
        console.log('Event '+evt);
        var accountFromId = component.get("v.recordId");
        evt.setParams({
            componentDef  : "c:AffiliateSaveForm" ,
            componentAttribute : {
                accId : accountFromId
            }

        });
        evt.fire();

Example 2: calling lightning component from another lightning component

console.log('Enter Here');
var evt = $A.get("e.force:navigateToComponent");
console.log('evt'+evt);
evt.setParams({
componentDef: "c:Component2"
//componentAttributes :{ }
});

evt.fire();