What is the meaning of the below mentioned terms ? Are they any different from each other?
Update :: Re- constructed the question
As per my understanding the above terms mean the same thing. I have read the documentation but haven't clearly understood it.
Found an awesome link to my questions.
AEM URL Rewriting The typical website structure for an Adobe CQ5/AEM project begins with /content in the URL structure and typically contains the application name. My example application’s homepage has the URL structure /content/cookbook/en/home.html which matches the JCR structure for the website. This is not an ideal url path most people would like for their site. To address this concern we will utilize two methods for rewriting URLS within AEM.
Sling Resource Resolver Inside AEM you can configure the Sling Resource Resolver to filter out the initial path of your site structure. To achieve this you need to edit the Apache Sling Resource Resolver Factory inside the system console’s configuration section (/system/console/configMgr). You will need to add an entry under the URL Mapping property to remove the beginning portion of the URL you want remapped. In my case I have entered /content/cookbook/-/ so that /en/books.html now resolves the url /content/cookbook/en/books.html. This will apply to all sites within your site so you may want to review your site structure to avoid a conflict.
Vanity URLs
For some sites there might be a requirement to create a friendly url for navigating into your site. In my case I want to type http://localhost:4502/books to navigate to the /en/books.html page. In this scenario I may just decide to edit the Vanity URL property for the books.html page. I can specify that /books is the vanity url and any traffic to that URL will be redirected to books.html. This can be convenient for site with only a couple vanity URLs but isn’t idea since it can be edited by an author.
Sling Resource Mappings If you wish to keep url mapping rules outside of the author’s control then you should utilize the Resource Mapping features in Sling. Under /etc/map/http you can create nodes of the jcr type sling:Mapping that will allow you to do the same thing as vanity urls. These nodes require two properties to be set: sling:match and sling:internalRedirect. The sling:match property uses regular expression to evaluate the url to match. If the url is matched then the request is redirected to the path set in the sling:internalRedirect property. In the example application, the matched path localhost.4502/authors is redirected to the /content/cookbook/en/authors.html page.