Where is the 'book'?

Sorry if this is a noob question, but I always hear reference to a 'book' in chess, from which all theory comes from. Is this book a real thing or just a figure of speech?

Thanks! 

Figure of speech.

Playing in "book" basically means following opening theory.

https://www.chesscentral.com/pages/learn-chess-play-chess-better/chess-terminology.html

Book: Besides the kind with a spine, a “book” move is one that a player has learned to play in a particular position in the opening (from a “book” or other media) without the need to “calculate”.

Yes, as post #5 said. There is no one "Book"; there is a body of knowledge accumulated and refined for the last two hundred years. "Book move" refers to moves following accepted doctrine. Another term you'll come across is Line or Lines. These are accepted deviations/variations to book moves; you might consider them "forks in the road". When you read books on openings or tactics, you'll see these terms frequently. 

"Book Moves" generally refer to opening moves, or sequences of moves, that have been played before in high level chess. They have been tried and found to be reliable. There is no single, actual "book,"

And playing out of book means playing moves that are not in common opening theory.

And it's not a "noob" question, it's quite reasonable

Correct, it is nothing to be ashamed of. Many of us did not learn this until playing for many months or even years.

Lets see how many more times this question will be answered...

42

I would probably take the over on that...

I would add that the worst way of improving your chess ability is to get caught up in opening book moves. When I coached a very successful high school team, some of my players would memorize reams of opening moves only to play a game and their opponent would usually make a non-book move that was NOT a losing move within the first several moves.  Some would memorize traps they hoped their opponents would fall for, but the good players would not fall for them and my player often ended up in a poor position by playing traps.

THE way for a noob to get strong is to study mostly tactics: learn the patterns, names and be able to demonstrate them as well as some positions that lead to tactics. Here's a great place to start:

https://www.chess.com/article/view/chess-tactics--definitions-and-examples

https://chesstempo.com/tactical-motifs.html

https://chesstempo.com/positional-motifs.html

I is also important to understand the ideas behind some openings - there are lessons and videos here at chess.com and tons of them on YouTube and scattered throughout the internet.

Having a PLAN is also important as is understanding endgame principles, but the first major thing is TACTICS!

Loosely I'll use "book" and "theory" interchangeably and to simply mean the move has been played by strong GMs in classical tournaments against other strong GMs.

Nowadays a book move is any move recorded in the database on your computer. (Every serious chess player has a database).