It is a good idea that you are researching about Ping or having the interest about pinging. Hopefully i can give you the answer in this post.
In General term Ping or pinging is a web service. It is used to warn Spider and Crawler Indexer’s when a new page has been added or updated to your blog.
Ping service is a universal way for you to inform the search engines to Index your newly added or updated Blog post pages into their database.
The right way of using ping is only when you have a new post in your blog or website.
Reminders: Over pinging can get you black listed so it means that if you abuse pinging your website, you website might not be index.