Hello Everyone, In this post , I will let you know , how you can expose a lightning component in visualforce page and also pass value through visualforce page to lightning component. Here I am provide some code example that shows clear picture of this task. So let's begin,

Expose a lightning component in visualforce page
 
Key points to expose a lightning component in visualforce page are:
a) Add the <apex:includeLightning/> component in your newly created visualforce page.
b) Reference your Lightning app that decorated with your component dependency by using $Lightning.use() function. 
c) Write a function that created the component in the visualforce page by using $Lightning.createComponent() function.
 
Please follow the following step to expose the lightning component in visualforce page.
 
1. Open developer console and Navigate to File | New | Lightning Component and create a lightning component named ExposeInVFComponent and replace the following code. 
 <aura:component implements="flexipage:availableForAllPageTypes" access="global" >
    <aura:attribute name="PersonName" type="string" default=""/>
    <b>
        Output from visalforce page : {!v.PersonName}
    </b>
 </aura:component>
2. In developer console, Navigate to File | New | Lightning Application and create a lightning app named ExposeInVF and replace the following code.
 <aura:application extends="ltng:outApp" >
    <aura:dependency resource="c:ExposeInVFComponent"/>
 </aura:application>

3. Again goto developer console and Navigate to File | New | Visualforce Page and create a new visualforce page named ExposeComponent and replace the following code.

 <apex:page showHeader="false" sidebar="false">
    <apex:includeLightning />
    <input type="text" id="txtPersonName" value="Salesforce Blog"/><br/>  
    <div id="lightning"/>
    <script>    
    $Lightning.use("c:ExposeInVF", function() {
        $Lightning.createComponent("c:ExposeInVFComponent",
                                   { "PersonName" : document.getElementById('txtPersonName').value},
                                   "lightning",function(cmp){
                                       // do some stuff
                                   });
    });
    </script>
 </apex:page>

4. Preview your visualforce page to see the output.

Output:

Hope you like this post, for any feedback or suggestions please feel free to comment. I would appreciate your feedback and suggestions.
Thank you.