Client. vs Clientr.

[wild8900]

Hey this is probably a really stupid question but Ive never been too sure.
From what I know, clientr. variables are more secure but you can only change them serverside, usualy with triggeractions (pain in the ass). But Im told client. variables can be edited clientside.

I was thinking of using some values in client. vars, should I? Its quicker and doesn't use triggeractions. Less lag right?