What is the difference between Blogging and Vlogging. Can we earn money through this?

Blogging is pure text based. You explain everything with text. Vlogging is video blog where you use video to explain everything or mixture of video & text sometimes.
You can create a free account on blogspot and start blogging anytime. Here is a link i found http://www.shoutmeloud.com/how-to-start-a-free-blog-using-blogspot-com.html

For vlogging, you can create a youtube account (using your gmail id) and start uploading videos on your channel. For example people create youtube channels where they upload videos about cooking lessons, educational videos, etc.

Yes you can definitely earn money using blogging or vlogging. You need to link Google adsense account to your blog or youtube channel for that. Only thing which you should be aware of is that you should not copy content from somewhere else on the internet and add it to your blog or download someone's video and upload it to your channel. All content in your blog or youtube channel should be created by you. Also don't click on ads shown on your blog or youtube channel on your own otherwise your Google adsense account will be disabled forever and you won't earn any money.

Vlog:
"Vlog" is video log for short. The term "vlog" originally comes from blog because in the past, blogs are usually more popular but with YouTube available, people who are more interested in more action than just reading words, they turn to vlogs.
But in my opinion, I still prefer bloggers because when you read their words it's truly from their heart whereas when people are in front of the camera they tend to be more self-conscious about how they look and things like that, so their vlogging material may turn out to be 80% acted out.

*A blog originally came from the word “weblog” or a “web log”.
You can think of it as an online journal or diary, although blogs are used for much more now, like online journalism.
A blogger is someone who blogs, or writes content for a blog & Blogging is the act of writing a post for a blog.

*A vlog is a video blog post. The term can also refer to a blog made up entirely of video blog posts.
Vlog posts are created by creating a video of yourself or an event, uploading it to the Internet and publishing it within a post on your blog.

In short Blogging is the act of writing a post for a blog which is purely text based & Vlogging is video blog where you use video to explain everything or mixture of video and text sometimes.
Yes you can earn money using Blogging or Vlogging by linking your Google AdSense to your blog or youtube channel.