What is the expansion for computer? Common oriented machine particularly used to .....?

Answer 1

expansion for computer? hmmm ... a new piece of software or hardware I assume.
You need to ask a direct question about what you are looking for, otherwise - nobody will give you a good answer.

Answer 2

depending on your work space and your preferance. It is all good position as long as:
1. you feel comfortable accessing and useing the space around the computer.
2. the ventalation are not blocked by anything.
3. ALL the screw are scre in tight on all moving and/or removeable parts.

as long as all part are secure in place and no ventalaion problem and you are happy with the position than it is all good.