Below code from the website module in models dir contain website.py file

def _render(self, cr, uid, ids, template, values=None, context=None): # TODO: remove this. (just kept for backward api compatibility for saas-3) return self.pool['ir.ui.view'].render(cr, uid, template, values=values, context=context)

def render(self, cr, uid, ids, template, values=None, status_code=None, context=None):
    # TODO: remove this. (just kept for backward api compatibility for saas-3)
    return request.render(template, values, uid=uid)

Explain above two method and how it works in website module ..?? and website_mail module use this in controller and return the

return request.website.render("website_mail.designer_index", values) AND return request.website._render('website_mail.email_designer_snippets')

what is the difference for in website_mail module