Meta tag helps your blog in Search Engine Promotion

Meta tags are important for Search Engine Optimization because Google and other search engines might use them as snippets for your pages. A page description Meta tag gives summary of what the page is about.  It might be a sentence or two or a short paragraph. It might help search engines to find content and to matching up with a user's search query. 

Structure of Meta tags for description and keywords:

<meta name="description" content="Description of your blog"/>

<meta name="keywords" content="Keywords related to your blog"/>

Keywords should be separated by commas

Add a Meta tag in to your HTML:
1. Modify the colored text, according to your blog.
2. Open Blogger Dashboard in blogger --->> Next click your blog Design option --->> click Edit HTML.
3. Find <head/> tag and Paste Meta Tag just below it. Click Save Template.

You should remember following things:

1.  Don't fill description with only keywords.Search engines will ban your site from their listing. So use distinct,related and informative description.
2. Avoid writing a description Meta tag that has no relation to the content of your blog.
3. Using generic descriptions like "Page about"or "This is a web page" are not recommended.
4. Don't Copy and paste the entire content of the posts into the description Meta tag.
5. Repeating keywords again and again may give negative result.