A Meta Description Tag has practical relevance for SEO for it tells search engines what a particular page is all about. This is how the meta description tag looks like:
<head> <meta name="description" content="This is a concise summary of your post that may show up in search engine results."> </head>
When we talk about search engines, we tend to focus on the 'Big 2' - Google and Bing. As far as optimising your page for Bing is concerned, meta description tags are of paramount importance. In other words adding meta description tags to your posts will help them rank high in Bing Search results.
Google, on the other hand, does not expressly require you to incorporate meta description tags for each of your pages or posts, however, doing so will always be an added advantage.
Adding a Meta Description tag to each post in Blogger.
Earlier, adding a meta description tag for each blogger post was practically infeasible (you had to add tons of code). However after Google introduced some sweeping changes to make Blogspot blogs more SEO friendly, adding a meta description tag is no longer a concern - the process being simple and you're even freed from the trouble of manually adding codes.
1. Open the 'Post Editor'
2. On the right sidebar under "Post Settings" locate the "Search Description" tab. (See Image)
3. Click on the "Search Description" tab, enter your 'description' for the concerned post in the box that shows up, click on 'done' and you are good to go. (No need of adding codes manually)
Tip: Edit all your past posts to add a meta description for each of them - doing so will help improve their visibility in search engine results.