How can I embed an Editor just like those in StackExchange Q&A in Drupal 7? I am new to Drupal.

I want to embed an editor in my content, body nodes so that I can do different editing when I add a new content. (i.e., bold , hyperlink, list) etc.

Is it possible to do that? Any module is available?
Yes, there are quite a few.  One of the most popular editor modules is WYSIWYG which allows you to choose which JavaScript library you want to use, or there are more specific modules such as the CKEditor module