How Kazakhstan has become a non-permanent member of the UN Security Council?

The website of the UN Security Council meets readers with a slogan: "Welcome to the United Nations. It's your world". And this is indeed a whole world consisting of the General Assembly, the Secretariat, the International Court of Justice, the Economic and Social Council, the Trusteeship Council, the United Nations Postal Administration, and many other specialized agencies. The most important body is the Security Council, which  has the primary responsibility for maintaining international peace. And all members of the United Nations must obey its decisions.