in short, meta description will tell the search engine's crawler what is on the certain blog
it is also picked us as snippets in the search result and as the description when you share the post on Google+, Facebook, Twitter and other social networks.If you properly write a meta description your post will be on the top of the search results and get more visit.

Steps

1.go to blogger Dashboard
2.go to your Settings and Search preferences
3.under Meta tags go to Description and click the Edit
4.Click the ‘Yes’ button.
5.Enter the meta description for your blog.
6.Click ‘Save Changes’ button.


and that is it... now your blog is more visible for searches.