COMMENT: "We say...
"Op-/Ed pages" - opinion and editorial (US terminology)
(a) Leader (leading article) "Editorial" (we do not use this term. "Editorial" = all none advertising matter. Unsigned. Voice of the newspaper. Eg The Sun Says... (normally pegged to lead news story. Separation of comment and fact. Written by specialist "leader writers".
Examples... every newspaper, every day. Magazines... letter from the editor, etc.
(b) Viewpoint. By-lined piece by somebody well known or interested. Daily Mail – "Talking Point Journalism". Often linked to reader response/letter (especially online, because of e-mail).
BBC news online describes how "talking point" journalism works in new media here:
Part of "War View" series (Afghanistan):
Washington Post’s (famous) OP/ED pages. NB – feature cartoons (also comment on Op/Ed pages).
(c ) Feature cartoon (an art in its own right, the political cartoon)
4. Satire, Parliamentary Sketch, London Life… etc – lightweight journalist essay.
The absolute classic satire (all since is a copy). Swift’s "modest proposal" (1729)