I don't get what the chamber of secrets really is.

[Lisa]

Why can't the basilisk just come out of the pipes whenever and kill all the time? Why does it have to be opened? How did he who must not be named find the chamber in his time at Hogwarts?
Voldemort did a lot of research into the Dark Arts and found out he was an heir of Slytherin and searched the castle for years before he found the entrance in the bathroom. It has to be opened because the snake is enormous and would only be able to fit through the entrance.

I get that mudbloods will die when it is opened, but how? Just the basilisk?
The basilisk can kill just by looking at someone but it also has very sharp and venomous fangs.

So Salazar Slytherin locked a big snake with petrifying/killing powers up, with the idea that it will kill mudbloods, but wouldn't it kill anyone it came across who looked at it? So the Secret to the chamber is a basilisk?
The secret of the chamber is that it has a secret entrance, no one knows where it is AND it contains a monster. The basilisk doesn't live in the chamber all the time (it is hatched, so Voldemort likely hatched this one), but snakes live long lives and can go an incredibly long time without food so it was mostly feeding on mice and animals.

Who controls the basilisk?
The chamber is only supposed to be able to opened by an heir of Slytherin himself, and he is supposed to control the snake and tell it which students (and teachers I guess) to kill. The only person to die during Voldemort's time was a muggle-born (Moaning Myrtle) and when Ginny was opening the Chamber she couldn't control it which is why it was attacking indiscriminately.

[Davidbrok3]

I never really read the books as a kid so for my entire life I've known Ginny to be pretty much just Harry's wife.
https://eur.mconvert.net/usd
But I'm reading OotP for the first time and she's super likeable. The little detail about how she's great at quidditch because she snuck rides on her brother's broomsticks adds so much character about how creative and capable she is.

[Qiyi]

EmmettChase wrote: "Maybe I missed something all along, but what exactly IS the chamber, other than a big series of tunnels with a snake-guard? I get that mudbloods will die when it is opened, but how? Just the basili..."
Ok, you. Let's get one thing straight. JUST because when YOU read the words don't penetrate that thick skull of yours does not mean that we all read like that.
The chamber of secrets is a secret chamber(No duh) that Salazar Slytherin built while he was still at school. Because Salazar could speak Parseltoungue, he was able to control the basilisk alone to get him to go after mudbloods. Remember, Slytherin valued pure blood wizards, so he did not wish for the basilisk to attack them. And no, the reason it was called the chamber of secrets was because no one knew how to open it, unless the true heir of slytherin came to Hogwarts.

[Solianne]

1. Why didn’t Riddle order the basilisk to kill the muggle-borns when he had the chance? Why just petrify them?

2. Why didn’t the school teachers ask Moaning Myrtle the same thing Harry asked to discover the entrance to the chamber? Did they literally ignore the fact that she was killed by the basilisk and most likely knew where it had come from (the pipes)?

[Jamie]

Solianne wrote: "1. Why didn’t Riddle order the basilisk to kill the muggle-borns when he had the chance? Why just petrify them?

2. Why didn’t the school teachers ask Moaning Myrtle the same thing Harry asked to d..."

These answers are solely my opinions and take aways from reading the series multiple times.

1.) Tom Riddle did order the basilisk to kill the muggle-borns, the students were petrified not on his command but because they didn't look directly into his eyes. This was also depicted in the movies when they demonstrated Hermione using the mirror to look around corners, and how Nearly Headless Nick shielded a direct view, or the camera that got fried- but prevented death.

Warning: some spoilers may be included in my response to your second question if you have not read the entire series.

2.) I believe it is likely the professors did ask Moaning Myrtle. Though it is never clearly stated that they did, I think one could make the assumption that at the very least Dumbledore would have asked her. He seemed to have an idea of how the basilisk travelled through the school, and I think that is likely one of the ways he would have come to that conclusion. However, it is very clearly stated none of them could find the actual chamber. The reason for this is because none of them could speak Parseltongue. It is noted in the books, and briefly in the films; speaking Parseltongue is very rare. If you read the whole series you later find that Tom Riddle found his ancestors and killed them, they could speak Parseltongue, we know that Tom Riddle himself could speak it, and we know that Salazar could speak it. The only reason Harry Potter could speak Parseltongue is because he had part of Riddle's sole imprinted into him when his mom threw herself in front of the curse for him. Once the series comes to a conclusion, and Harry defeats Riddle - after that time, Harry could no longer speak Parseltongue, because it wasn't actually his gift, it was part of the Dark Lord that was imprinted into him, connecting them.