If you update your CV in a job website, will it improve ur skill of preparing CV that will catch the eyes of Recruiting Manager or Employer?

Updated CV always catches the eyes of recruiting manager, updated cv shows your active job seekers and looking for change.

An updated and relevant CV will surely get the attention of recruiters and employers. Be sure to update and highlight your experience, expertise, and skills in your CV. Check your grammar and spelling when you revise and edit your CV.  

only experience is to be added, all the recruiters rewrite your CV to there standard, and they are all different...

You need to be updated with the changing world. updating cv is also a kind of that. It helps highlight your cv and recruiters get noticed by that. Not an old cv is facinated by the recruiters.

If it is relevant to the job.