how does 'jQuery form plugin' + 'jQuery plugin: Validation' and 'jQuery CKEditor Plugin' "assist" each other?

how does 'jQuery form plugin' + 'jQuery plugin: Validation' and 'jQuery CKEditor Plugin' "assist" each other?

Hello,

'jQuery form plugin': http://jquery.malsup.com/form/
'jQuery plugin: Validation' : http://bassistance.de/jquery-plugins/jquery-plugin-validation/
'jQuery CKEditor Plugin: http://www.fyneworks.com/jquery/ckeditor/#tab-Support

among these 3, the most confusing part to me is: both -form plugin, and validation - do form validation and both upload files. then why do I need the 'form plugin'? since they overlap so much, do they work properly with each other? I guess I am also not sure about what difference does a ajax form submit makes (i.e. form plugin)?

and finally, how does it all playout with:

1. jQuery UI
2. HTML5 forms

sorry if too many things here, but i guess I just confused...

thank you.
Rajeev