The Bible is really a collection of 66 books.  The word biblia in Greek just means "books".  It's also often called Scripture, from the Latin word for "writings".  It's split into two sections, called testaments or covenants.  The Old Testament comprises 39 books and spans the history of the world from creation through to about 450 BC.  The New Testament starts with the birth of Jesus Christ and was completed between AD 90 and 100.

It's often called the Holy Bible because it's devoted to - or set apart to - God.  More than that, it claims to be God's word to us - his disclosure, or revelation, of his plans for the universe, this world, and mankind in particular.  It contains many different types of writing, including history, poetry, law, proverbs, and letters.  And these were written by many different sorts of people: prophets yes, but also, for example, kings, shepherds, fishermen, a lawyer, and a doctor.

But, crucially, it tells us that all these people were moved to write by the Holy Spirit(1).  Specifically, they were writing about the Christ, or Messiah, who was to come (in the case of the Old Testament(2)) or who had been gloriously revealed in the person of the Lord Jesus (in the case of the New Testament(3)(4)).  The Bible exists, then, to teach us about God, how he expects us to live, and - most importantly for us - how we can enjoy an everlasting relationship with him through the Lord Jesus Christ.

There have been many translations of the Bible into English from the original languages (principally Hebrew in the Old Testament, and Greek in the New Testament).  Unfortunately, not all of these have been faithful to the originally intended meaning - people with their own agenda have applied their own spin.  So, if you're thinking about buying or reading a Bible, it's important to use one that can be trusted to bring across the originally intended meaning.  On this site we use the New International Version.  The Authorised, or King James, Version, has been used for many years and is perhaps the most well-known English version.  However, the modern reader may find its language a little hard to understand.  The New King James Version is an updated version of this.