Help with wordpress image uploader

Up till now, I've been using an ftp program to upload images and use the from url feature to add the image to the blog post.

1. Is there any advantage of using the "Add media files from your computer" feature.

2. When I use the "Add media files from your computer" feature, I notice that it uploads the original image and 2 additional images, a 150x150 thumbnail and an intermediate size image. Is this normal?

 

Yes it is, one for the photogallery thumb nails looks and when you click to bring the big image.

 

You can disable thumbnails via "Media" option and setting all values to 0

 

Yes, that is quite normal. More over, it is a plus.

 

!. It's faster (not in terms of upload but rather usability)
2. Yes it's normal