The terms Major Prophets and Minor Prophets are simply a way to divide the Old Testament prophetic books. The Major Prophets are Isaiah, Jeremiah, Lamentations, Ezekiel, and Daniel. The Minor Prophets are Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, and Malachi. The Minor Prophets are also sometimes called The Twelve.
The Major Prophets are described as “major” because their books are longer and the content has broad, even global implications. The Minor Prophets are described as “minor” because their books are shorter (although Hosea and Zechariah are almost as long as Daniel) and the content is more narrowly focused. That does not mean the Minor Prophets are any less inspired than the Major Prophets. It is simply a matter of God choosing to reveal more to the Major Prophets than He did to the Minor Prophets.