Keywords are an important concept to understand as a blogger. If used appropriately in your blog title and blog content, they can have a huge impact in the type of readers you are attracting.
A keyword is any term that is directly related to the subject you are talking about. So as an example:
Subject - Board Games
Keywords - board games, monopoly, monopoly strategy, monopoly rules, how to play monopoly, where to buy monopoly, board game blog
Words that are not keywords - rules, strategy, how to play, playing, Alain's blog
Now this is a very basic example. But notice how the keywords are both specific but at the same time broad enough that someone might type it in on the internet. The words that are not keywords are broad. "rules" or "strategy" could apply to anything in life that has either/or. Also, no one will type in my name plus blog unless they already know my blog exists.
There is a chance if you blog becomes popular enough that if someone were to type in a broad term, your blog could come up as relavant. However, there's no guarantee that the person will click on your blog. And there's an even slimmer chance that they will become a blog regular.
You have to think about what the purpose of your blog is. What interests should the ideal reader have? Title each and every post with this in mind. It also doesn't hurt to have some keywords in your actual content.
You want to make it so when someone types in one of these keywords online, your blog is the one that pops up as the most relavant site.