Around the time of Jesus, a Jewish sectarian group of about 200 lived at Qumran near the north-west shore of Dead Sea. They started settling there during the reign of John Hyrcanus, about 100 hundred years before Jesus was born. They might have been the group that was called the Essenes.
They practiced the Jewish religious rituals, studied the scriptures, copied the scriptures and other religious materials, and wrote their own books. They stored the books in the form of scrolls in clay jars in the caves.
The settlement was destroyed around 68 AD, when the Jews revolted against the Romans. Jerusalem and the Temple was destroyed and Jews driven away. The books laid hidden in the caves until they were discovered in 1947, the year Israel became independent.
These are the famous Dead Sea Scrolls. About 40% of them are copies of the Hebrew Bible, the “Old Testament.” About 30% are Apocryphal books such as Enoch, Jubilees, Tobit, ... And then another 30% are sectarian books such as Community Rule, ... The most important were the OT books, of course. Some of the OT books were written only a few hundred years before they were copied and stored in Qumran. They were as close to the original as one could realistically get.
They are extremely important for many reasons. They are the oldest surviving copies of the Bible. Their discovery helps to show that the Bible has been preserved essentially unchanged for thousands of years. They were hidden when Jerusalem and the Second Temple was destroyed. They laid forgotten for almost 2,000 years. They surfaced again when the modern nation of Israel regained independence, which was a miracle by itself.
I felt privileged to have been able to see the settlement, some of the caves, and some of the scrolls themselves - even though I could not read the writing, which was in Hebrew, Aramaic and Greek.