Think of embedding as creating a little window in your web page that allows you to see your video as if it was on that page, without having to upload it again. The video will have the YouTube logo on it.
To embed a video in one of your posts:
First, locate the video on the site to which you have uploaded it.
Next, you need to find the code for embedding the video. On YouTube, this is clearly posted beside each video.
Select the code in the Embed field and copy it to the Clipboard.
Now, in Blogger, create or edit the post in which you wish to embed the video. Instead of working in Compose mode, select the Edit HTML tab to work in HTML mode.
Paste the contents of the clipboard into your post and publish.