Manga?Doujinshi? I don't get it.

What's the difference?
The two buttons are confusing me.
Which one am I suppose to click if I wanna read something?

Mangas are usually original works. Doujins are based on existing series like "insert your favorite anime here".

Oh. Then it's either I'm reading a perverted manga, or a perverted manga "parody".

Case closed.

Uhm... not really... Ones an original 'perverted manga' one is a 'perverted manga' based on an anime, game or manga. Parody implies comedy

Originals aren't based on an existing series. They're original stories with original characters.

Doujins are fanfics.

Essentially it's this:

Manga is just manga. Original works.

Doujinshi are fan-comics. Not always hentai, but a good chunk of doujins are hentai.

Well, there's a bit more to it than what people are explaining here. Dōjinshi are any works that are self-published, a product independent from the regular industry if you will, sort of like indie games and movies. Manga is in essence simply what people in Japan would call the comics of the western world, so you can have a Dōjinshi manga and what we refer to as just Dōjinshi are actually manga at the same time. When someone refers to Manga without Dōjinshi attached to it, it usually means a work published within the regular industry and they are often original works because it is difficult and costly to obtain the right to publish a work about currently existing content legally, but, there are cases where artists are given the right to publish works based off already existing content, usually through some contractual deal which allows whoever holds the copyright to the work a share in profit.

When you hear of the term Circle, it usually means a group of independent artists working together, though it can and uncommonly but not rarely is one person working behind an alias.

That's not what Ex and G.E say.

And this shows what different from what I said?

That parody doesn't necessarily imply comedy in those sites.

It doesn't mention parody anywhere on there... as far as my crappy eyes can see

Right under language...

Ooooh, there we go. My finding skills are known to be shit.
Also:
noun (plural parodies)
an imitation of the style of a particular writer, artist, or genre with deliberate exaggeration for comic effect:
the film is a parody of the horror genre
[mass noun]:
his provocative use of parody
an imitation or version of something that falls far short of the real thing; a travesty:
he gave her a parody of a smile
verb (parodies, parodying, parodied)
[with object]
produce a humorously exaggerated imitation of (a writer, artist, or genre):
his speciality was parodying schoolgirl fiction
mimic humorously:
he parodied his friend’s voice

A good handful of the doujins here have pretty funny endings.

Then to be a bit more accurate, Doujinshi tend to be Hentai manga which had an Anime/manga to make up the characters to, like Lucky Star or Elfen Lied.

While Hentai manga in general are original pieces of work, with original characters and setups, not so different from the mainstrea ones like Gintama, and KissxSis, only being a tad too perverted for normal audiences.

Yes, but parody is more a 'take the piss' funny instead of something that goes with the story/ you can understand them saying.

IE; a parody would be doing something the main characters of an anime do, but doing it absolutely retardedly/ in a really stupid way, showing all the things they do that annoy people.
example:

That's a parody of gumby. only thing related is the characters/ it's the video of the episode, not the audio

I know, I was only pointing it out ;_;