Because of the publishing practices of the time and the fact that playwrights, including Shakespeare, didn't write with the intention of preserving their plays but with the goal of making money, it is difficult to pinpoint definitive texts. In Shakespeare's case, only about half of his plays were published during his lifetime. In fact, it wasn't until 1623, seven years after Shakespeare's death in 1616, that all his plays were assembled into one volume. This collection, referred to as The First Folio (because it was printed in folio format, the largest, most expensive, and most prestigious kind of book), included previously published plays as well as plays never before published. Some of the works in The First Folio can be traced to the author's papers, yet some were re-created from prompt books (annotated play scripts) or even the memories of the actors themselves (helping to explain some of the inconsistencies found in different editions of the plays).
