General questions regarding the WD MY BOOK

I am a new user with the WD MY BOOK external hard drive.

 

1. Can I delete folders and files on my laptop after i have stored them on my  MY BOOK WD external drive?

 

2. In the manual for the WD MY BOOK it states the following: Do not use this product as a portable drive.

    Does this mean that I can’t hook this up to my laptop and use the information that I have or will store in it?  Which would be folders or files, and future downloads such as movies.  Most importantly I want to pull up documents that         may have important information for me to use.  And I do not want to keep it on the laptop.  Please help.                

    Thank you

You never want to use one drive internal or external as the only copy of important data.

Joe